I have never been on a coach trip but I have been to all these places under my own steam, so to speak. I just rented a car and took off !
Self drive holidays in the States are really easy. The roads are almost empty, the cars are well-equipped and the fuel is cheap. The accommodation is very affordable in Motels and you will meet the ordinary people, rather than lots of other tourists
If you can't do that, then pick a tour that is less ambitious. The main trouble with these coach tours is that they try to see too much, in too little time. Its the equivalent of seeing Edinburgh and then starting out for Bath the next day, seeing Bath for about an hour and then driving to Lands End !
Take the Grand Canyon for instance. Its nowhere near anywhere ! But to spend hours driving there and then have just 90 mins is daft. Say at each of the National Parks for 2-3 days and really see what's to be seen.
These coach trips involve most of each day, watching this wonderful scenery for the windows of the bus, driving from each "comfort break" to another !
Give it some thought Fishy !