A slide camper is likely to overload any SRW truck. If that wasn't the case, I would love to have one. Given the weights you've mentioned you're likely to be close since you have another 1,600 lbs of GVWR that I don't have. I would personally like to have 1,000 lbs for gear after weighing truck and dry camper, and it looks like you don't quite have that but are probably close enough.
If you think that you can be out on the road only mildly overloaded, you may consider it. Also take a look at that Arctic Fox mentioned above as well. It competes strongly with the 855S.
Then again, on my most recent trip I saw a guy with a slide camper on an F250. I guess anything is possible....