The cheek weld issue is why you see shotgun stocks with the add-on cheek piece. It's can be an issue if you don't build something up for a cheek rest; especially if you use a cantilever barrel.
You didn't say what kind of barrel or slugs you're using. Slugs in an 835 can be an issue due to the over-sized bore. Are you using a dedicated slug barrel? Does it have a cantilever for the scope? If you're mounting just to the receiver you'll have to be careful keeping the barrel mounted tightly. The barrel can move around in relation to the receiver. That'll open your groups up a good bit.
The last shotgun scope I set up, I used Burris Signature rings on a cantilever barrel. The rings worked great with a shotgun scope. Shotgun scopes are lightweight because a heavy scope will move under the heavy recoil. A heavier scope is nigh impossible to hold in place.
If I were to do it again without a cantilever barrel, I'd use a rib rider mount directly on the barrel with a small red dot sight.