Like everything else depends upon what you want it for and how much you want to invest. Probably top of the line is 220v Ingersoll-Rand models--if its for use on rare occassion you could get by for a lot less dollars--oiless are noisy because the cycle so frequently, if you plan on doing lots of body work, etc the noise, and lack of consisent power to the tool will drive you nuts unless you wear ear plugs, or sound muffs.
If you are just going to use one to install a piece of equiptment,or put on or take off lugnuts a smaller unit would work.
You building a automotive garage--or just a car hobby one in your two/three car garage?
But what the heck do I know I've only worked with the smaller ones in Construction for 35 years--and the small 6gal Cambell-Hausfield has been the best I've had for a number of years--used on construction sites from powering framing guns to finish nailers and on occassion filling a low or flat tire--and breaking loose parts on a car or truck
