I've banged on about them before, but try Mazzei, in Fresno California. They have cheap (and good) PA38s and can offer you cheap accommodation in apartments near the airport (although I didn't stay there).
The airport is in the San Joaquin valley, but it tends to suffer from low stratus I'm told in the winter, so take some additional advice before going out there (or anywhere) as the year drags on. I understand Florida is a better prospect for WX in the winter....
Good luck and have fun!