This list of great players is endless but, if you want to understand Jazz, I seriously recommend you got back to the giants. Sart with Ray Brown, Paul Chambers, Doug Watkins, Scott LaFaro, Charlie Haden, Ron Carter etc and, when you move on to the cats Jaywalker is talking about (who are all monsters and amoung my favourite players). it will make more sense. I think if you start with Gary Peacock, you may struggle with the kinds of gigs you are most likely to start with