I suggest Denver as your starting point -- and British Airways has non-stop service there from London. This places you in position to see the Rocky Mtns and southwest USA enroute. You could ride the narrow guage (excursion)railroad at Durango, Colorado, see Mesa Verde National Park, Monument Valley, Grand Canyon, several of the national parks in Utah (Zion, Bryce, Capitol Reef, Arches, Canyonlands, plus Flagstaff, AZ and its many attractions, Las Vegas, Death Valley, Anza-Borrego Desert Park (NE of San Diego), the list is endless. It would also be great if you made a side trip to the south to visit Phoenix and Tucson! It might also be possible to do some skiing in the Durango/Telluride area or in Utah if we get early snows. The problem is narrowing your options to fit into the "limited" time you have! Bob