I wish you good luck with it. 4, 5 or 6 string? Bolt-on, set-neck or thru-neck?
Hee hee- these are all the things I'm mulling over!
At present (and this will undoubtedly change) I'm thinking 4string fretless with a Billy Sheehan style neck join (unorthodox bolt-on), 2 octave fingerboard with neck position P-bass pickup and piezo bridge.
"Music is in the air; it's my job to pull it out."- Jaco Pastorius