I did something very similar to what TL-Iguana did. at first a ran a external oiler, then switched over to a grease-able set up.
here is my build
http://forum.calgaryjeep.com/index.php?topic=16374.0 . You are going to have to look over the first set up and second to see the whole thing.
What are you wanting to do with the set up? unless you are willing to lose a/c or shell out the cash for a engine driven pump, you are going to be in the same boat as just getting the ARB or one of the other guys that are building the same thing. If the only resin is to run air tools, I have never used air tools on the trail. and to change a tire, you can spin the nuts off faster with a tier wrench . Kevin runs 2 sets of wheel, one street and one trail and changes in camp but he still uses the ARB. and if it is a setup to reseat a bead you can get a ARB, and a small CT pig and change it to be a reservoir for the air blast.
There is a lot of options and it comes down to what you are looking to do with the set up and how much cash you want to spend.
BTW a A/C conversion without already having tanks will set you back just over $200 budget for $300 to be safe. Brass firings and steal braded hose is not cheap even at PA. it all adds up in a hurry.