I've not flown in that neck of the woods for a few years so my knowledge of rental companies is old and I won't share it.
But, if I was doing it again (which I will sooner or later
) I think I'd be more likely to look to a base in Arizona than California - it'll open up more options, and you are a bit further from the joys of LA and it's smogs and crowded airspace. I did very well once renting from Prescot Love field in Arizona.
Also if it's not obvious, buy the local charts and airfield guide NOW, to get some serious thinking done early, don't wait until you get there. I'm pretty certain you can get them all from Transair or equivalents.
G