i play clarinet and want to switch to saxophone and play more jazzy music. I can't figure out which type of saxophone wuld be better for this? Alto or tenor? Does the pitch make a big difference? Thanks

i play both, and like both.
alto is usually a lot more melody/solo stuff, but tenor is really good for the low jazzy kind of sounds, and makes sweet chords. tenors also have solos though, and they can be awesome. i think tenors add a lot more of the tone or colour to any jazz piece.
it depends on what you're more into really.

I play Tenor saxophone.
All of the other kids in my class play alto.
Whenever you hear a famous saxophone artist, they are playing alto.
so bassically alto is more jazzy

BUT TENOR SAXOPHONES STILL ROCK OFF YOUR SOX!!!

It depends on what you whom you want to sound like. Their are many great Tenor Sax Jazz muscians.
John Coltrane
Sonny Stitt
Stan Getz
These are just to name a few.
Alto
Cannonball Adderly
Charlie Parker
Art Pepper
the list just goes on.
Alto/Tenor?
I would probably go with Tenor though. Sense the Key is something you will be familar with.