I have a Coats 5060A, and running off a 26gal C&H compressor at 125psi max. Got the machine at a local shop for $800. Never had an issue with it, and works for the first 2 tires, then the compressor gets behind and oyu have to walk away for about 5 minutes or so.
Have done everything from 205/50R15 to 315/35R17's and never had an issue with it. Always done it by myself and not assist arm. Probably the best tool investment I have ever made.
My recomendation is just start hitting all the local tire shops, eventually you'll find one guy that has been itchin' to get a new machine. Wal-Mart is always a good one to hit, as they usually replace them and leave the old one there for a while before it gets picked up.