Great, something I can contribute.
If you need to buy a gun, that means you probably don't hunt much, hence no reason to spend big bucks.
Mossberg 12 gauge pump, full or modified choke, less than $200 at your local discount store, heavy #6 shot if using lead, 2's or 4's if using steel.
My personal preference is Gold Hunter, sans plug, 3 1/2" T's.
Happy hunting.