Well....this is a question that has so many variables it is difficult to answer and I don't feel I am qualified to answer. However I have painted a few cars at home-including the vette in my avatar. But since you asked I will tell you what I think. I would go with an HVLP system. There are numerous ways to accomodate that, but the best way (again in my feeble opinion) would be to use a turbine system like Eastwood sells. http://www.eastwoodco.com/shopping/p...&keyword=34056
The advantage to this system is there is no way for oil to shoot into or under your primer job. If you do get oil under your primer or color your paint can have bubbles later as the oil gets hot and tries to outgas.

If you do decide to use a conventional compressor and gun I would still buy a pretty good one not a Sears or hardware store variety. I would still buy a good Binks, Devilbus or Sharpe HVLP gravity gun vs a siphon type.
http://www.autorefinishdevilbiss.com/main.php?p=g&id=7

But, since you aren't going to listen to me anyway. Get yourself one of those small standup compressors from Home Depot. I think they are an oiless compressor on a 25 gal tank. They are an upright design and have wheels so you can move it around. Be sure to buy a hose just for painting! Also get a good regulator with a water and oil trap. That with a good primer gun and you should be good to go.