I would opt for a tent for the boys. Another alternative would be a queen inflatable mattress for the living room floor.
We started 20 years ago with a 20' travel trailer and the 3 kids & their friends stayed in tents. The kids were about 12-16 at the time we originally purchased the 20 footer. They had a good time camping without sleeping inside and the handful of times any of them slept in the camper we just used the dinette. We've had two occasions since owning the 5th wheel (2003) where one of the kids came with us and he and his girlfriend stayed inside. They slept on the floor because it beat their tent that had a ripped rain fly. They didn't complain.