Congratulations!
We've done a similar trip. Its very ambitious. Plan to spend at least half your time driving. Figure every 100 miles is 2 hours. We did 15 days, from Milwaukee to Vegas, then the Monterey Peninsula, then Yellowstone. Each stop was 2 to 3 days each. It was a blast. But if I did it again, it would have to be a 3 week trip. Two just isn't enough for a trip like that.
You like hiking, do a trip to Yellowstone/Grand Teton, and Glacier National Parks. I think that's easier to do in two weeks and you'll have so much to see and so many places to hike it'll be overwhelming for you. In Yellowstone some of the best stuff is accessible by day hike but off the beaten path from the crowds. We spent 5 days there in 2006 and didn't see but a fraction of what there is to see in the back country. Stay in West Yellowstone, MT. Lots of great little restaurants there. We stayed at Grizzly RV park twice. Excellent RV park and 2 minutes from the park entrance.
Look on Amazon for "Best easy day hike" books. Those hike aren't always easy, but they are good hikes and very scenic.