I just finished my new garage addition (extra two bays) with a full size twin post lift in one bay and I bought the Champion 5HP Advantage series compressor:
http://www.tptools.com/prod_list_di...sors&mscssid=RQBWBQ17R4MV8LCKVKHJGQWLSSCUBS67
These some of, if not the best American made units available. They are sold by most automotive shop equipment suppiers (check the local yellow pages), the people who sell, install and service lifts etc.
I payed $1565 for mine delivered. I know this is serious money but this is also a serious piece of equipment that will last a life time and then some. I do run a bead blast cabinet (read uses a lot of air) off of it and it catches up with even it's air needs. Note that the pump is turning at 805 rpm's so it makes very very little noise. Best machine I have ever owned.