Obviously if your looking to shoot clays, you don't want to buy some featherlite shotgun. I like my guns to be in the 8lb range, give or take a few ounces. {7 1\2lbs minimum}
Use to be all you saw on the skeet fields were 26'' and some 28'' barrels. Now, 30'' seems to be the norm. If your primary game is trap, and your not buying a trap specific gun, you can still get 32's. More times than not, if you look for 32's, it's going to be a sporting model and will have ported barrels.
Fit of the gun is the most important thing. The sporting model tend to have longer length of pull than something in a field model.
Beretta has a ''newer" model out, the Silver Pigeon I, it is available with 28 or 30'' barrels. {non ported}It's basically the same as the rest of the 686 breed.