With the V8, your truck will be a considerably different tow vehicle. I have towed several cars on flat bed U-haul and other trailers with the old 4.0L V6, which used to be in my truck. When I swapped in the V8, I towed my old Nissan 4x4 stomper on another U-Haul and could not believe the difference. I could actually accelerate and best of all, I could maintain highway speed - uphill and down - as well as pass when needed. I really felt very comfortable. (This was before the Kenne Bell went on, so it was justa stock Explorer V8 with better exhaust.)
My truck has always had 4:10 gears in it, so even with those gears, I did not like to tow heavy loads.
As for brakes, there is not much option out there. You could get drilled or slotted rotors, but will not be the giant improvement you are looking for. The best bet is electric brakes in your own trailer or a Uhaul with the surge brakes. The surge brakes work very well, however, you do not have the override control to counteract swaying, as you do with electrics. The only other brake option is to do a custom Brembo/PBR/Baer/etc. conversion. That is actually really simple, you just have to buy new wheels to fit them ($$$)
Finally, as for the rear axle, you should be all set with the 8.8". I know the 95 and up Explorers have "big bearing" ends and thicker housing tubes than the ranger and mustang 8.8, not sure about the earlier explorer. This "big bearing" axle is the same axle used in the F150 and south american 1 ton Rangers.
