Here's the issues and steps I did to run the Toy IFS box.
Mounting:
I bought a mounting plate kit from trail-gear to help me locate the holes and have some reinforcement plates on each side of the frame, the supplied bolts with the kit aren't long enough for our application so I picked some up at my local ace, I also ordered a stick of 3/4" OD 1/2" ID DOM to make longer sleeves, I bet if you requested it, trial-gear would've probably sent longer sleeves that you could cut down. Before putting these plates on, you can look on an explorer frame and find these "flared" out portions on the side of the frame rails where you would put the box. I'm assuming these are to help strengthen the frame. I cut out a piece of 1/4" steel plate with windows to lay over the outside of the frame rail and welded it in so that i'd have a smooth surface to weld the outer plates for the box. On the inside of the frame rail I didn't have the luxury of welding in a similar piece of steel to give me that smooth surface due to how ridiculously close the radiator hose would be to where the forward bolt would go through. I cut 6 3/4" holes for the sleeves, I recommend a hole saw... a 3/4" drill bit isn't the way to go. I put the plates on each side, ran the sleeves through and put some bolts up to see how the IFS box would mount and to make sure the pitman arm wouldn't hit my panhard bar mount. The pitman arm I bought from polyperformance.com, they get it from sky-manufacturing, it's reamed for the chevy TRE but not the DLE, I had bought the correct reamer already so I just reamed it out for the DLE. After all that, I welded on the plates on each side, the inside I just pretty much filled the gaps between those flared out portions and the plate. I installed the IFS box and noticed that I had to trim down the forward mounting bolt due to how close it was to the radiator hose and I THINK I cut down the nut too.
Pitman arm: The pitman arm and box combo offers enough throw for a D44's steering.
Hoses: I purchased hoses from PSC motorsports, I bought the high pressure hoses that you can put together yourself. The fittings on the box are 16mm inverted flare(HP) and 17mm inverted flare(LP). I bought the adapter fitting for the HP side to go to -an 6 and a straight hose barb for the low pressure side. The hose barb touches a bolt on the a/c compressor... and that's after I cut that bolt's stud off. So to fix that, i'm going to make a spacer plate to space out the box a little more from the frame and try out a 45* and 90* hose barb. The stock 5.0L PS pump will work, ford calls it their CIII pump. I tried to use the piece that goes into the pump on the stock hose and a 16mm o-ring type adapter fitting I had. I cut off the 16mm part of the adapter, drilled a hole the size of the hard line on the stock hose, then I put the hard line in there and welded it to what was left of the adapter. I actually couldn't test this setup since I didn't know that my replacement PS pump was a no go, plus I didn't know how if that welded part of the adapter would flow that well. So I found a place after looking through many forums who makes an adapter from the ciii pump to -an 6. The company's name is Lee Manufacturing, they deal with power steering setups. I ordered the adapter and bought a sealing washer they sell, that washer replaces the teflon washer that goes on the original fitting. His number is (818) 768-0371, he's located in California. After I got that fitting, I ran the HP hose I made to the steering box, the LP side goes to some 3/8" hose to my stock power steering cooler that's currently only zip tied to my new crossmember I made, then from the cooler back to the stock reservior. I've also got my setup done for hydraulic assist.
Steering shaft: I didn't want to skimp here and weld two shafts together. Let's go back a little bit, with the torque monster headers and my 3" body lift, the steering extension for the body lift would NOT clear the headers, so the fix this problem, I ordered a collapsable "D" shaft from borgeson and their mustang single u-joint. This solution worked well, I had to remove some material from inside the u-joint because it doesn't fit our explorer's rack 100%. I did have slight rubbing, depending on where the steering wheel was turned too, of the bolt that holds the D shaft to the steering shaft coming out of the firewall on the header. Since i've had experience with the borgeson stuff, I picked up another piece of telescopic shaft and a 11/16-36 spline u-joint(toyota IFS box joint) and built another steering shaft.
Performance: Even without the ram hooked up, it does a decent job turning the 39.5s on pavement. With the ram it's absolutely amazing. Problem is that I can't turn all the way to the right, that's because my tires rub on the pitman arm. I ordered some wheel spacers to hopefully fix that problem even after I space out the box from the frame to clear the compressor bolt. Do note that my front D44 is a 77 F-150 44 that I cut down approx 6" on the pass side.
Out of all the things I did on the SAS, i'd have to say that the steering box was the hardest part for me to do. I definately recommend removing the radiator for more space down there when welding but to also periodically set it back in there to see what kind of space you're working with.
The rest of my steering is a high steer setup using parts mike super arms on flat top knuckles, all chevy "1-ton" TRE and DLE, inverted T steering setup, 1.5" OD 1/4" wall DOM with weld in bungs. Problems with other high steer arms are that they don't move the tie rod out front enough, it'll hit the coils, but I don't know if that'll be a problem with coil overs or if you're even going to go high steer. I'd say making it high steer ended up being more of a headache than anything else. If you look at my tie rod and panhard bar, they're REALLY close to the bottom of the oil pan, they isn't very much real estate down there. Another thing is that even though i'm running an inverted T, there's no way I could have pushed the panhard bar mount on the frame out any further or made my panhard mount on the axle and furher away so I could run a panhard bar of equal length and equal angle to the drag link. You might not have this problem, it all really depends on the radius arms you use or how your suspension links mount, since you're going coilovers, they make brackets that weld to the axle tube and the inner knuckle so at least those will be spaced away.
Everything on the steering and panhard bars are fully adjustable so it can be aligned(toe) and I can adjust axle placement(side to side). I haven't experienced much bump steer but I think I can attribute that to the hydraulic ram.
Things I haven't fixed yet: My radius arm's tubes are pretty close to the torsion bar pad(greenish blue thing) retainer AND it doesn't look like a front d/s would clear the xmsn crossmember so i'm planning on making a new crossmember that'll clear the d/s, eliminate the torsion bar pad retainer, AND use a polyurethane xmsn mount because my stock one was completely annihilated to the point where my drivetrain lifted up and slammed into the floor of the truck.
Like you and everyone else said above, our frames are pretty straight so... to have enough room below the oil pan and frame rails, you'll still end up with a tall explorer, my explorer has a 3" BL so if you did do an SAS, yours would at least not be so tall.
I hope this helps you on your SAS, i'll take some pictures of it when I get back from colorado(i'm currently on pre deployment leave). If you have any questions, i'll be glad to help.