If you can shoot or at least shoulder as many shotguns as you can to find a gun that fits you. That would be key. If you're sure you want an o/u a used lanber or cz would be a good shotgun if you don't want to up your budget and go with a browning or beretta (or similar). If you're thinking about trap and skeet I'd recommend at least 28" barrels. Adjustable chokes would be very helpful for a multi-sport shotgun. Also don't rule out a 12 gauge. 12 is a little better for trap and if you reload or plan to you can load shells down for less recoil for skeet (if recoil is your reason for wanting a 20). I would caution against stoeger or mossberg o/u's. I don't recall seeing either hold up to serious clay shooting. I've seen several break or have problems where they had to be sent back to the factory. As others have said, a used remingtion 1100 would also be a good shotgun for what you're planning to use it for if you go the semi auto route. Good luck.