I've got a nice Squier s-s Jag that I'm thinking of upgrading to be a properly-giggable back-up bass. Playability is very good as received and I've fitted a set of Hipshot ultra-light machines I already had, which has improved tuning and balance. As you would expect, the basic OE pups and pot's are pretty limited in terms of the range and quality of sounds they deliver but, never having changed pups, I just don't know what's out there. Any suggestions as to what would give me a significant improvement at a reasonable price? This would be used for classic rock/pop covers, so I need some vintage tones on tap.