Great trip. One issue, though, could be crossing the Sierras in winter. Re rental, see some of the suggestions further up in this thread.
Do you hold an FAA license? If not, you'll need a 'based-on' one, search here, there are numerous threads discussing this.
If you've never flown in the US, and especially in the LA and SF airspace then you'll need a bit of training and a good checkout. Plan some time for that. Make sure you know how to operate the GPS unit(s) in the rental a/c and/or bring your own handheld with the Americas database loaded. Register on
FltPlan.com Flight Planning & Flight Tracking..
Happy flying!