I'd stay away from a 20 gauge, that handicaps a beginner in skeet/trap.

I personally shoot my M1 Super 90 with a 24" barrel, and its all covered in camo. I get some funny looks from guys shooting expensive single shots/doubles, but at the end of the day when I've beat the majority of them, their "snickering" stops.

It all amounts to what gun fits you the best. Go to the gunshop, and have him get out a bunch of shotguns and tell him what you want/expect out of a gun, and go from there. Benelli's feel the best in my hands, and a Beretta or Remington, etc might feel best to you.

Heck, baaack in the day when I was a youngin I won the state jr division shooting a Browning BPS Stalker.