I use a vintage (late 1950's) 12 Ga. Browning Superposed but a modern Citori is also a fine Trap gun.

Some have suggested Pump's and I'd recommend staying away from them not because I dislike them for hunting and/or HD - but for Trap and Skeet why beat yourself up with more recoil than necessary? They do tend to have much harder hitting recoil IMO and you will be firing quite a bit at the Trap game.

The Remington 1100, 11-87 or similar are great guns, but since you will be loading only two rounds at a time, a semi auto has little real advantage other than light recoil.

Just my opinion of course - YMMV.