Fretboard change?

[glefty5]

Hi,
got a question about fingerboards. Here's the goal, I have a medium scale faux fender dinky jazz bass with a rosewood, 20 fret neck that I really want to have a 21 or 22 fret maple board on. How much $, time n hassle is it to get a new fingerboard put on the existing neck? I want to use the existing body, pups, etc coz the ergos n sound r great but wanna make it into my dream 4 string. The neck joint is 2&1/4" wide, a 1/4" narrower than a Warmoth neck joint is so no go there it seems. Also, if I go for a full 34" scale neck, I assume I'll need to have the bridge moved back towards the rear of the body but there is only 1&1/2" to play with.
Any advice, encouragement or brickbats appreciated.
Thanks, Glen

[glefty5]

Hmmm, I'll simplify & not ramble on as before.
1) About how much to replace a fretboard with a maple cap, fretted or fretless?
2) If I replace a 32" neck with a 34" neck, must the bridge be moved back 2", 1" or not at all?
Thnx for any info, Your Rodentship!