Upgrading MIM P Bass

[epy]

Hi folks, I am looking to upgrade my old MIM p bass. I am not a hundred % positive on what I should add into it. Id like to put in darkstar but have no idea about routing or the actual size specs of the darkstar pickup I am more or less capable with the electronics side of things. Is it worth swapping in a gotoh or bad ass bridge? I play through a larger Trayner MK II YBA stack and get a pretty decent tone right now (with new strings...). I like having a good amount of natural overdrive from the tubes In My tone and think a darkstar would really boost my signal. Are there any other pickups that are comparable?

Thanks!