I am looking to scrounge together some new pickups for my bass (P neck, J bridge). Definitely passive. Now, it's not that hard to find a bridge jazz or a precision pickup and have them installed. However, I am a bit concerned about volume and phase issues etc (probably other things that I also know nothing about) that may arise with two different pickup types. Since most of the P/J sets that I have found are not appealing to me, I was looking into grabbing each pickup seperately. *So my question is, what should I be worried about exactly? And how could I go about avoiding buying 'conflicting' pickups?