#1
Hi, im thinking of switching the pickups of my squier jazz bass... Does anyone have any suggestions?
#5
Honestly? If you don't have an amp that will take advantage of the nuance of a new set of pickups, you won't be too pleased.

What model of Jazz Bass and what amp are you using?
Fact: Bears eat beats. Bears beats Battlestar Galactica.
#7
The rumble 100 ain't bad, but it really doesn't highlight the tone of the wood/pickups on basses as well as higher end amps. You might be more inclined to investigate higher end amps to get the tone you want, rather than doing pithy upgrades to parts on your bass.

Try looking into something Ampeg or Eden for an amp and then, after getting the amp and becoming acclimated to it, look into some pickups intended specifically for the type of music you play.

Which begs the next question: what style of music do you play?
Fact: Bears eat beats. Bears beats Battlestar Galactica.