I think I've settled on the Puma you have listed, but from a local dealer whom I have discovered a connection with. I can get a supper deal on it, so it's hard to pass up. But if I had intentions of running a DA sander and/or paint guns very much, I'd probably step up to a 2 stage. Obviously that $1400 Quincy would be great, it's 15.4 CFM @ 100 PSI, 2 stage, and 100% duty cycle. It's the best one on your list by far, but I'm not sure it's worth the difference in cost to you or not. It's on sell for $1299 today, btw.
You might also look at the Puma PK560VS
. It has a higher CFM than any on your list and reasonably priced. It's neither a 2 stage nor 100% duty cycle though.