Bart Schematics & Info
I suggest you get in touch with the folks at Best Bass Gear, if you give them your pickup's model number, they should be able to help you out.
Also, I only have one bass with Bart pickups without an onboard preamp; my Rickenbacker 4001, it sounds good, but I intend to put stock pickups back into it.
I have three other Bart equipped basses that have onboard preamps, and I really love the sounds of all three.
You mentioned your budget's a bit tight, perhaps once you get the schematic you can have a friend who's adept at reading them and handy with a soldering iron help you. Don't feel alone, I'm in the same boat with schematics, and I have zero soldering skills.
Nobody seems to like the 36"scale...but 34 will never do. Players will tolerate 35...not as good as 36, but ***--gotta sell, gotta sell. -AJ