you CAN do colorado just have to avoid certain parts and research will tell you about them. The 'million dollar' highway is one to avoid if you have any fears of looking down, there are several 10000+ft passes but most are tree covered and wont bother ya. even going across Wolf Creek pass you dont have but maybe 1 or 2 high overlook places. Southern utah is real nice again research what ya want. Forget the road but its out of escalante co to the highway up by loa. It can be intimidating as you are on the spine of a ridge but the road is good (we were on a motorcycle) and we actually ran into a cattle drive going down the roadway. Pretty neat. cedar breaks is around 10000ft and you DO look down into a crater so avoid that maybe? Make sure you go to Teton NP, and stop in jackson for the national elk refuge. They have a great visitor center and its well worth the time to visit.