And plenty of time to do it and enjoy every moment.

It is such an amazing area you will love it, the area you are covering passes by so many wonderful National parks and as Lifey mentioned below an annual
pass from the NPS will save you money, normally after your first 4 visits to any park. Here is there website that is full of info about the parks and accommodations as well as being able to check what is or isn't open. Just click on the map to link to a park in that area.
As an overseas visitor the pass isn't available on line but you can purchase it at the first park entrance gate you go too.
As well as the Grand Canyon, check out Yosemite, a few hours from San Fran, it shouldn't be missed out. A few hours from Vegas you also have the beautiful parks of Zion and Bryce canyon.

If you have an idea of your routes, you are more than welcome to post them up and maybe we can point you in the direction of some 2hidden gems".

Dave.