| First, filling out your profile would give people a much clearer idea of your level of experience, and would allow answers better suited to you individually.
That said, if you're a brand-new beginner to jazz, there's really no 1 bass player that has "easier" lines than any others. There's quite a number of threads on this forum regarding major jazz bassists, and Paul Chambers is definitely one to listen to (as is Ray Brown, Ron Carter, Jimmy Blanton, Oscar Pettiford, Red Mitchell, Scott Lafaro, etc...).
If you have access to the album "Study In Brown," there's a tune on there called "Sandu" where George Morrow's basslines are pretty clear and easy to hear. | 
