Trap Guns
One Lady Trapshooter once told me Trap guns are like men. Before you find your handsome prince you have to kiss a lot of frogs
In my own experience Trapshooters go through a lot of guns before settling on the right gun. Then spend the rest of their lives looking for the perfect gun. Trapshooters change guns like most people change clothes. They are never satisfied.
I would recommend shooting what you have and trying as many guns as you can. Ask if the range rents guns, most do and this will give you a feel for several guns. You might want to visit other ranges if you can. Ask other shooters about their guns, most will yak for hours why their gun is best.
Once you decide on the gun you like spend the $150 or so to have a fitting done by someone competent, the money is worth it as a competent fitter will be able to determine the right measurements for your body. It's like a good suit, you wouldn't spend $700 for a good suit and not have it tailored to you. Same with a Trap gun. (Or Skeet or Sporting Clays) Trap guns are generally set up different than other guns, higher ribs and stocks etc. You might want to look at a specialized trap gun (ruger has one in their catalog, although I haven't seen one yet).
Get a copy of "Blacks Wing and Clay", you can find it in any good bookstore. I get mine free because my club is on their mailing list. This book lists people who do fittings and has lots of other good info like ranges and manufacturers of firearms. It pays for itself.
Good Luck and have fun!
Geoff Ross