I am an advanced beginning bass player. I have an old Washburn Bantam XB102 PJ bass with a p bass type neck that feels very wide. I'm getting ready to begin lessons with a pro who is a 5 and 6 string aficionado. A local shop with a great reputation is selling a MIM Fender jazz bass and an Indonesian made G&L 5 string with active electronics. Which bass would be best to learn on? I want to play classic rock, blues, and one day jazz. I like the feeling of the jazz bass neck. Would I be better off getting accustomed to a 5 string neck? Both of the basses in the store are used but in excellent shape. My Washburn has developed a crack in the fretboard but has had a set-up. I appreciate your advice.