yea those compressors you have are probably the 2 slowest comps on the market. Also I see you have compression fittings. I have never had any luck with those and allways run PTC(push to connect) fittings with a good thread sealer preferably loctite 545.
Viair compressors are the way to go especially the 480 dual pack. Top of the line compressors.
http://www.illusivefabrications.com/html/modules.php?name=catalog&file=index&cPath=28_46 if you cant afford the 480s then I would suggest the 380s. both run at 200 psi which will give you a longer play time with a given tank size and more lift if your making out at 150psi now. Air Zenith compressors have had way to many issues in the past for me to reccomend. I do not have any experiance witht he new AZ except for the fact they are pretty expensive.
Slam specialties are the best bags on the market the RE series is plenty for what you need. all the higher rated slam bags are for hopping with high pressure. The new airlift Dominators are also good bags. Be sure not to confuse them with the chassis tech Denominator ii bag. its basically a cheep copy. Firestone and Contitech are also good bags but they don't get the lift slam specialties or dominators do.
Another thing I notice is thats the compressors dont have the factory leader hoses on them which most have a stainless line with a check valve in line. The check valve between the comp and the tank prevents air from backflowing or leaking out the head of the comp.
Also did you bag the truck or buy it bagged? That 2 link on the rear suspension is going to be a killer on your driveline.