TromboneChat

I'm looking into finding a leadpipe for my Q30 that would be good for jazz, but im confused by the different materials offered. If anyone could please explain what the different materials might do?

The Q30 is a large bore (if I'm reading the Q series page correctly), so typically you wouldn't expect that to be used in a jazz context, although there are some notable exceptions where some players work with larger instruments (Steve Davis, Steve Turre, & Slide Hampton come to mind).

In any case, there are a lot of materials available in leadpipes. The brassark.com page has a lot of interesting info:

http://brassark.com/leadpipes.html

Beyond that, I've found the Shires page about materials to reflect my experience too:

[Unmarked]: yellow brass—ideal balance of brilliance and warmth for most players, clear and articulate (the overwhelming majority of S.E. Shires players prefer yellow-brass leadpipes)
N: nickel silver*—brilliant and clear, crisp articulation and response (can limit timbral flexibility)
G: gold brass*—warm, dense sound, rounded articulations (can limit clarity)
SS: sterling silver*†—strong fundamental and presence of sound with clean, simple overtone presentation, clear attack (can lack warmth and brilliance)

For commercial stuff, I would probably stick to Nickel or Yellow. Or perhaps copper... I have a nice Copper 32H pipe in my 3B that works pretty well.

I use a shaved down Bach 36 for my 6H and it plays awesome. I use a MK Drawing NIckel 50 pipe for my 62H and it really makes the articulations speak.

I hear that certain leadpipe materials go well with certain bell materials (eg rose brass bell with nickel leadpipe).

I think that you would be better of leaving the lead pipe alone. for more of a jazz sound on the large bore tenor, consider using a brighter sounding mouthpiece, hopefully one with a shallower cup. This will do more to brighten your sound than any change in lead pipe. Of course, if you are playing in a traditional big band the best thing is to get a small-bore tenor. If you are you using a large bore tenor and the others are using small bores than you can have a situation where, by the time you are playing loud enough to pick up bite and color, you are too loud for the section. If you are in a combo and are the only trombone, the large bore can work well, as long as you have a horn/mouthpiece combo that has color and lights up when you want it to. But don't try to achieve all this with just a lead pipe change, you'll more likely just muck it up.

If you want a somewhat brighter sound, I think Nickel Silver is the only material that might add that. However I would like to echo modelerdc's idea that getting a smaller horn for jazz may be better. Regardless of leadpipe material, with a .547 bore horn with a 8.5 inch bell, if you want it to have edge and zip, you're gonna blow away the rest of the section.

Might suggest a used Yamaha YSL-354. Dillon Music has two, including one from the rectangular case era.