I'd suggest about anything gas operated.
Start here ^^^^ end here ^^^^. Maybe invest in a top end recoil pad. With a 20ga that's getting all the recommends it should be fun. NEVER shoot turkey loads off a bench with a fixed breach shotgun unless you find the odd one that allows an upright shooting position. 99% I've ever seen were way, way too low forcing the shooter to hunch over forward putting your collar bone, joints, cartilage, even your face in a bad position to take recoil. The further forward a shooter leans on a bench the more non-responsive to recoil he becomes. But you already learned that. As others have said shoot off sticks or sitting with elbows on your knees. Good luck this season. Hope you get one just a little smaller than mine
