SPB1 is a great reference...should be able to find a used one most anywhere online fwiw.Dear @soulstar89 .. if you like bass-oriented P-bass pickups, with a distinctive Motown character, I’d definitely give the widely available Fender PV ‘63 pickup a shot.
If you like a bit more midrange and a bit less bass, whilst keeping that peculiar vintage taste, you may wish to try a Seymour Duncan SPB-1 pickup, a bit underestimated in my opinion but a very fine sounding pickup.
Going up a little step .. well .. definitely the Klein Epic ‘62; it has got all one may want from a P-bass pickup IMO.
Ive compared SPB1 to my buds 64 Fender P bass (which is crazy light slightly under 8lbs) in several basses he owns...its close and i agree a bit underestimated...my SPB1 is in a late 80's USA Peavey Fury which is light and i think poplar body, 2 piece maple neck w RW board...it sounds really good and its light, right at 8 lbs...sounds like a proper P bass.
The Peavey Fury had a SPB2 hot wind (yes it IS HOT) Duncan that just did not sound right at all for a traditional P sound fwiw.