Re: about mouthpieces
go to a shop and try some out. There is nothing anyone can say that should influence what you try or buy as it's a 100% personal thing and different for everyone.
No certain mouthpieces go with certain saxes.
I think the only information you need is
1. what sound do I want to move towards (remember you make the sound, the mouthpiece makes it easier to produce the timbre you want)
2. is the price an issue or an asset?
3. Do I play nice and in tune with this set-up? (you play in tune not the mouthpiece, some will make this easier than others)
4. is the tone consistent throughout the registers?
5. can i control the saxophone dynamically as well as I could or better than before the mouthpiece change?
6. Do I need a harder or softer reed with this?
7. will a different reed make it even better (add more edge, smooth it out etc.)
8. Do I want this mouthpiece for one specific horn or a couple? if it's two you would want the best one overall across the two saxophones. or if you can afford it buy two.
9. does it feel comfortable in my mouth?
10. lastly look at the brand and size after you've made your mind up. Is it a respected manufacture with decent quality control? What is the situation with returns if I decide I don't like it? DO I want mouthpiece patches?
with your own personal answers to those questions you can find the perfect mouthpiece for you and your current horn(s)