I didn't know we had so many SS shooters on the TDR. These guys know what they're talking about!! If you get a gun to fit you properly, I don't care if its a JC Higgins, you will probably shoot it well. Guys say a gun kicks them bad, more than likely it doesn't fit them. You should be able to shut your eyes, and throw the gun to your shoulder and open them and see the perfect sight picture, if you don't, it doesn't fit properly. Most guys shoot a gun that is too long for them, if you are a right hand shooter, when you swing to the right it will throw you off.
When I started shooting sporting clays, autos were not too popular, because back then if you had a miss fire or jam, you lost the target, I think they have changed that rule now, I haven't shot for about 7 yrs. Fajen built a lot of stocks for me, and when you shoulder the gun, where your thumb grips over the stock, your thumb should be no farther than a 1/2 " from your nose, or enough that your thumb does not hit your nose from the recoil.
As for what gun to shoot, thats up to you, and what you can afford. I started shooting competion trap 40 yrs. ago with a La Fevre, single bbl. made in 1921, and sold new then for $25. 00. Went from that to Ithaca's, Brownings, Ljutic, Berretta, bought a Rottweil about 20 yrs. ago, now have 4 of them, had one OU choke tubbed, and use it for Clays. Anyway just make sure the gun fits you. A lot of the gun dlrs. have adjustable stocks now, so they can fit one to you. Good luck
Larry