I see those SnS folks around the Ramkota during season and know a few people that have done the SnS pronghorn hunt from Casper. You will not need much (if any) gear other than your rifle, ammo, bipod, range finder, and binoculars. Camo clothing is not needed, but a pair of leather gloves and some tweezers might come in handy. Don't be surprised if your "guide" speaks with an Alabama accent and has a regular job in Alabama as a firefighter, but most of them seem like nice guys. I hear that one of the Alabama guys has moved to Casper a few years ago and now runs the pronghorn hunts. After a bit of driving, shooting, and photos you will be heading to Pat's for meat processing.
The guides will use the SCI method for estimating the hunters' trophies, so don't be too surprised if you put a tape on the horns later and are a bit disappointed by the B&C score. Ramkota has a nice included breakfast, and an OK restaurant for dinner.