A C trumpet is not just a shorter version of a Bb horn. As you learn your C's characteristics--intonation and tonal qualities, you MUST develop a sense of what you want that horn to sound like. At that point, a different mouthpiece might make that sound easier to produce. You can't really perform on your C until you can make it produce the tone you want. Ditto for the Eb and especially for both sides of the pic. I'm currently searching out the "new me" on a Schilke P 7-4 after 30 years on an Andre era Selmer. The sound has to happen inside your head before it can come out your horn.