DiMarzio was first to offer replacement pickups for electric-guitars and -basses and since the early 70s still holds its position with a successful combination of tradition and innovation.
The combination of the J-Modell at the bridge and the P at the neck (actually it would have to be in the middle of the middle) has become the most popular pickup combination for bass guitars since the 80s, simply because the strengths of the two most popular bass design are combined here: The subtle, middle tone of the J on the bridge and the powerful, low-pitched punch of the P-model in front - you do not really need any more.