You can do the AZ deal and keep the car for 2 weeks. But it sounds like you want an additional 10-11 days beyond that.
Here's an idea: Pick up the AZ driveout car from a neighborhood store in Phoenix. Set your return location to a neighborhood store in Los Angeles. Then open a new contract at the neighborhood store for a one-way to SFO for the additional days. This will avoid the airport fees at PHX and LAX.