Maybe I'm simplistic but this Kobalt impact has never let me down.
http://www.lowes.com/pd_100966-47120..._-sgy%20air134
I use it on my 60gal/170PSI(set to 150psi) upright. A couple of drops of bostich oil before use and it's good to go. I think that it is rated for 90PSI so I keep the regulator dialed over 10 at 100psi.
I am not a full time mechanic. I am merely a computer engineer who set out one Saturday morning for an electric impact and came home with the compressor. :/