Sounds like you're looking for a new "clone" of the British game gun concept: 12ga, straight grip, double triggers, relatively light. Well, you've got the Beretta 471, but it will cost you about twice as much. The Weatherby Athena d'Italia isn't as much money, but I think you'll find they're somewhat heavier guns. (But you should look at one if you can--might work for you.) Merkel 47E is another good one, but about in the Beretta price range--and if you're going to spend that much, then you also have the AyA 4/53. Beretta, Merkel, AyA--all right around $3,000. Weatherby about $2,000.
Newlyn, the reason I suggested used--and I stress again, NEWER used, to stay away from vintage guns with short chambers and other issues you may not want to deal with--is because there are so many really good guns out there, for what you're paying for a new Uggie (or even less). Ithaca SKB 280E, if you don't mind a beavertail forend and a single trigger; BSS 12ga Sporter, although they're somewhat heavy for a "game gun"; various models by V. Bernardelli, especially the sideplated Roma guns, but also the Gamecock; postwar Merkels, Sauers, and Simsons, although you have to look a bit to find one with a straight grip; the Zoli-Rizzinis Abercrombie & Fitch imported, although most of them did have a round knob rather than an English stock. If you buy from a reputable dealer, they'll stand behind what they sell. That's definitely the route I'd take.
