I'd like to have the best setup possible, too! So, here's my answer:
"Nice to hear from you! Well, that's a tough question...Its very individual. If you look at a list of famous players on any instrument (especially woodwind) the setups tend to be all over the place. Generally speaking, Jazz players use a more open tip and a lighter reed than classical, but a bigger part is having a 'jazz tone' in your head, and adjusting your timing, attack, phrasing, etc. to reflect a Jazz concept. Who do you listen to? Buddy DeFranco? Artie Shaw? Lots of listening and practicing with playalong tracks will help the most...
Now that, being said, its harder to get a Jazz sound on Vandoren M13 mpc with #4 reeds - that's a pretty closed, stuffy setup. I've used Bernard Portnoy mouthpieces on my horn and with students and had good results, either the BP02 or more open BP03 facing. These can generally be found on ebay for about $40 used. Also, an older Selmer HS** (2 stars, not one) gives a nice tone and is open enough to give some flexibility. If you're interested, I have some good mpcs on my site right now, as a retiring player parked a bunch of stuff with me to sell.
Also, don't forget reeds! I'd try a Fibracell 3.5 synthetic, or, if you really prefer natural reeds, look at a non-classical cut from Alexander: they make some really nice reeds cut specifically for a Jazzy sound."
How's that for an answer?