you know, I do not know the difference between cool jazz and smooth jazz. I guess I'm pathetic! But I can at least point you towards some for sure jazz:
Neskvartetten: http://www.ocremix.org/remixer/neskvartetten/ - these guys are fantastic. Drums, organ, guitar, sax.
Estradasphere: http://www.ocremix.org/remixer/estradasphere/ - fantastic quasi-big band arrangement of mario 2
Shnabubula: http://www.ocremix.org/remixer/shnabubula/ - Not everything he does is straight up jazz, but everything he does is greatly influenced by it. He's a fantastic jazz pianist. Some things more up your alley include Starflake Jazz, Samus Bubblebath, Pegasus Boots, Sugar Water Purple, and In the Beginning There Was Jazz.
Red Tailed Fox: http://www.ocremix.org/remixer/redtailedfox/ - I wouldn't say he's straight up jazz, but he's heavily influenced by it.
Joshua Morse: http://www.ocremix.org/remixer/joshuamorse/ - Honestly more smooth jazz, but still some great influences in his work too.
That's all I can think of for now. Happy Hunting!