Hi Jo,
I have done the National Parks, Canyons and Little Big Horn trip and America's Golden West. You would enjoy which ever one you choose.
In my opinion the National Parks, Canyons and Little Big Horn was the better trip. The scenery was absolutely fantastic and the opportunies to see wild life made it more exciting.
I really enjoyed the Golden West trip; I loved San Francisco and Universal Studios and the drive along the Pacific coast was great.
You get to see the Grand canyon (awesome!) and Las Vegas (Fantastic!) on both trips. You spend more time in Las Vegas with the Golden West trip.
I did the Golden West trip first and then the Parks trip.
You would probably be amongst the youngest, if not the youngest, on the trip but in all the holidays I have done with JY (six in all) age hasn't played a big part. Everyone mixes together whatever their age.
Regds
Jim