It's my experience that a Class B is not big enough for two people to go full time. But it is big enough for one person if it is well designed. jcussen's link included a Winnebago Ravel with a 5 gallon cassette toilet. That would not do for me.
California does not have to check everything, they have this great thing called hot line to the EPA, report the vehicle with license and locaton and get a summins in the mail to have your vehicle inspected. Happened to me twice already and had to prove that my DPF and EGR was fully functional and no soot was being emitted, guilty till proved innocent .... Got love it !! Did not matter I passed all smog checks and documents to prove it.