Hi Friends, just got Fender J Bass Marcus Miller 4 string, and would like to upgrade it to: Sadowsky OnBoard Preamp and New Pick Ups. So what do I do: Bartolini and if so which one ? Sadowsky and if so which one ? This bass would be used in a Live Situation with a Rock Band THanks and sorry If you heard this question few times, I just could not find the adequate answer yet! Appreciate it !