You are really going to have to go some where and try a bunch of mouthpieces. I tried Stork for a bit and didn't like them. My sound became "airy" for lack of a better term. I could play on it, but I just didn't like the sound I was getting on the piccolo, Bb and C trumpets. That is just me. Other people I know sound great on them.
I switched to Warburton mouthpieces 2 weeks before my Master's recital last year and haven't looked back. And still, other people sound less than desirable on the Warburon's that I use.
The unfortunate thing about mouthpieces is that you don't know until you try. Many places do have a test period. Try
http://www.mouthpieceexpress.com
I would suggest the following: Schilke 14A4X, 14A4, 14B. Warburton M, S, and SV series.
I would imagine there are other folks that would have some good recommendations on GR, Bob Reeves, Giardinelli, etc...
Don't forget, you are getting opinions from other players on mouthpieces that work for them. Just because Maurice Andre sounds incredible on a 7EW doesn't mean you will sound just as good. I remember, years ago, that one of my friends found out what size and make Severinson played. The funny thing was that only one of us could get more than a 2 octave C scale out.
Good luck in your search.