The timescale you have outlined is plenty to do what you are looking to do. I can recommend a Travel Book that is based on Road Trips between the various main places you have mentioned. It is an old book, but well worth having, for a Road Trip.
It is Nelles Explore the World - U.S.A. The West, Rockies & Texas and the ISBN is 3-88618-416-1, this will let any decent book shop order it for you.
As an example they give you a route LA to the Grand Canyon, via Zion, Bryce Canyon / Glen Canyon. Also LA to San Francisco along the coast road via Santa Barbra, Big Sur, Carmel, Monteray Bay, Salinas, Santa Cruz and San Jose.
Well worth the investment.
I will be pleased to offer any assistance, as I have the area on 3 occaisions.
Best regards,
George