First, you have the right idea about time: September (after Labor Day, when the kids go back to school) is probably the best time of year to outdoors in the West. Mosquitoes and flies are mostly gone, crowds are much less, the weather is typically glorious (although it is high country, so the weather can be ...). You won't be able to fish all the great places, but you'll be able to hit a lot of highlights. And don't be intimidated by the distances. A motor home will save you a lot of time checking into and out of motels. Yellowstone National Park, aside from its wildlife, thermal wonders, and spacious vistas, is a concentration of some of the best trout streams and lakes in America. The Henrys Fork in Idaho, perhaps the best trout stream in our fair land, is less than an hour from the park. Silver Creek and other fine streams near Sun Valley are just a few hours farther; the famous trout rivers of s.w. Montana are even closer. Eastern Washington and eastern Oregon (great trout lakes, famous steelhead rivers) are a half-day's drive away. If you keep food locked in your motor home, bears won't be a problem. Crime is always possible, but unlikely. Never leave your vehicle unlocked, or worse, with the motor running! A nine-foot rod with a variety of 6-weight lines will be your workhorse. You'll have a lot of fun with a 3- or 4-weight (7-9 feet). And if you can afford it, a 7- or 8-weight rod (9-10 feet) will be valuable for steelhead, salmon, and Is-this-wind-ever-going-to-quit? You may not be familiar with float tubes/belly boats. They are your affordable, portable entry to limitless trout fishing in smaller lakes. You really should get one for each of you. Man, do I envy you! And as you return to England, you'll envy us. Tight lines!