Re: PJ bass pickup tone
If you've just gotta mod your bass, you really can't go wrong with Quarter Pounders. (What? Somebody on a pickup site, wants to change pickups? Shocker!) I would also say "just play it until you know what you want", don't spend $ you don't HAVE to...
That being said, my #1 bass is a PJ with "Select by EMG" pups in it. They're the 80's version of EMG-HZ (passive) pups. The Selects came in lots of lower-end stuff so they get no love, but I think they sound great. Real crisp, almost "hi-fi" sound, super clean. You can always add dirt, but you can't make your clean signal cleaner...
Oh yeah, another thing about PJ setups is the P is a Humbucker, but the J usually isn't, so sometimes the P can totally overwhelm the J, or at least be noticeably louder. The EMG set I have is all Humbucker so they balance well. Lowering the P and cranking the J as close as you can, helps.