First, Welcome to SOTW.
Second, beware of SOTW! Aside from whether or not the Mk VI is the greatest horn every made, or Yamaha's are lifeless and shrill sounding hunks of doo doo (and there are quite a lot more heated debate subjects here too), you've perhaps started on one of the most hotly debated subjects on the forum..."which mouthpiece is best?"
We will all offer our opinions of what is best, but those opinions are based on what's best for us...not for you. First, listen to lots of players and try to develop a sound concept that you dig. That may change over time, especially as you develop as a player, but YOUR sound will start to ring in your own ears...shoot for that. Then go to your local music store (or stores) and don't take ANY money with you. No cash, no plastic, nothing! Try a bunch of mouthpieces and form your own opinion of how each piece either gets you closer to or further away from YOUR sound. If that's your approach then it won't matter if it's a Meyer, Otto Link, RPC, vintage, new or from Mars.
Oh, and enjoy yourself! This should be, after all, fun.