Engine driven is the way to go, I've put two yorks in two trucks (and s10 and a nissan hardbody) and they are leaps and bounds ahead of electric. They are a little more involved as far as mounting and plumbing but when your low on air and just hit the gas pedal and you can see the psi needle moving, its all worth it.
You can usually pick them up at a junk yard for 20 to 30 bucks or at a parts store for around 150 to 200. Now as far as parts you will need for them here they are:
(I'll post links at the end for all these parts)
1) Port adapters
Depending on which york you have they will either have top or back ports. On the back port models you can tap the head for a 1/2" npt fitting or buy adapters that will convert the hole to a 1/2"npt. On the top port models everyone usually goes with the adapters.
2) Check valve, leader hose and safety valve
You can pick these up at your local hose and supply store and the check valve and safety valve will run you 5 to 8 dollars each and the leader hose will be around 20 to 40.
3)Oil and water trap
You don't have to run a water trap but it will just keep the air tank dry. The oil trap is a must. The yorks are notorious for blow by and there is an oil mod you can do to the compressors that gets rid of almost all blow by but you will still see it in the trap from time to time.
As far as any other supplies its the same as any other air setup. I will say if you want to increase the life of your york I would use a Square D pressure switch with the pressure release (same thing thats on your garage compressor) on the york. What it will do is as soon as the comp shuts off there is pressure that is built up between the head and the check valve, this pressure switch will bleed that off. Same as when your home compressor shuts off and you hear that hissing sound. Its just saves the seals in the compressor head from having a constant 150 to 200 psi pushing against them.
Here are a few links to get you started.
Oil mod
http://www.rockcrawler.com/techreports/york_mod/index.asp
Compressor fittings
http://www.kilbyenterprises.com/compressors.htm
Also a good thing to know is there are 3 different displacement yorks, in your case you want the biggest because you have plenty of room for it and air up time will almost nothing as compared to the smallest. Easyiest way to find out what you have is take the pulley off.
If the snout of the shank is beveled on the end its a 206 the 06 means 6" of displacement.
If its beveled then its a 209, 9" of displacment.
If is straight then its the 210, 10" of displacement, this is the one you want. this thing is capable of putting out 4cfm at 90psi at around 1100 to 1300 rpms.
If you have any more questions ask away!
Heres a pic of that york I put in a nissan, it was a little 206 but it barley fit!
