I use a 6 hp / 60 gallon Campbell Hausfeld. It is about the best you will do until you step up to the 2 stage, which starts at about double the $400.00 amount you have been talking about.
I have stripped with a DA 3 or 4 cars completely, in addition to spraying and everythinh else I do, about 10 years old and no complaints.
When buying the 5-6hp 60 gallon units, there are several, many use a one piece aluminum pump that is not rebuildable, I recommend the cast iron pump, as in my C/H it comes with a manual listing part numbers for every single part. Best of all, I got it at WalMart for $369.00, they still have them, only about $389.00 now.