Mouthpiece Recommendations/help/guide.

I've been playing sax for five years now, and bari for two. I'm looking for a new mouthpiece, as mine is a simple plastic student model. I'm having trouble finding help online on my own, as I don't understand all the information being thrown at me, and I can't make too much sense of the mouthpiece review thread due to the fact that it's just like having a ton of names thrown at me.

Here's what I'm going for
-fast, easy response in any dynamic
-ability to play well in any dynamic
-ability to play really really loudly
-ability to play overtones
-dark, warm, growly sound
-usable for both classic and jazz

I use Vandoren(blue box) 3 1/2 reeds(sometimes 3s). I can play with very good air support, so that shouldn't be a problem. I was leaning towards the brass plated mouthpieces. Any help, tips, etc. is appreciated.

Also, what do the numbers signify in mouthpiece names(eg 6, 6*, 7, etc.)?

Thanks,

-Wylocson