If you guys all ready have the equipment ... you might want to look into Mom's Motorsports. They are out of Michigan and will make arrangements to pick up a group like yours near the Mich, Indiana, Ohio area. You can either jump in the truck with them or they will haul your stuff and you can fly in. They get great rates on lodging, food, transportation etc. ... it's something to look into. They make trips just about every to every other week to some destination out west.
I always feel you can't beat Togwotee Mountain Lodge as you just need to fly into Jackson Hole. The lodge will pick you up for free if you are staying a few night's. It's an senic hour drive to the lodge and they have rentals and everything you need right there. If you are up there for a week you won't need to leave once and riding is just across the street.