I picked up a $20 fretless thats mechanically sound but the electronics are a total mess. I was planning on putting in a whole knew setup and was wondering what I should know about mixing and matching p-ups and preamps. The bass is some sort of Aria but the finish on the headstock is a little messed up. As you can see from the picture, it currently has a weird PJ setup where the P is more like the size of soapbar and no knobs/preamp to speak of. I have no qualms about drilling new holes or widening a p-up slot to accomodate something new. Any suggestions for two decent but affordable p-ups and a preamp? Do certain pickups only work with certain onboard preamps?