As I read it, you can buy a T/C Contender, but you can't buy the stripped frame. It must have a barrel at least 6" already on the frame, and total package must be 10.5 or more. Unless you have a weird tiny custom barrel, any T/C will meet this requirement.
However, there's some nastiness about the combo .45/410 barrels in CA, something about them being short-barreled shotguns. Until you dig up more info on that, I'd stay away from T/C shotgun barrels under 18".
Aside from the shotgun or pistol/shotgun combo barrels, and standard T/C barrel should do you fine, so long as you purchase the frame with a 6"+ barrel already in place on it.
That's just how I read it, as a former CA resident and current T/C owner.
-MV