Rumor has it there is a good aircraft paint shop at the RYV airport halfway between msn and mke. You can probably find a phone number for the place in a handy AOPA guide. When I drove out there on Saturday they were stripping a T-6 and several other planes were awaiting work...like usual. My buddies dad had his Bonanza painted out there, no complaints. There's always planes out there getting painted, so the reputation must be good.
Also, on the east coast, there was a pretty good shop just north of Charleston SC. But I don't remember the name of the place. A google search should net a location for that place.