Strictly my opinion, but I listened to the P pickups (being a P player myself!), and here's how I ranked them:
5. - Nordstrand NP4 - $115,. bestbassgear.com. The brightest of the five, not really my cup of tea.
4. - Jason Lollar P - $110, lollarguitars.com - sounded good, but overpriced IMO.
3. - DiMarzio "Model P" DP122 - $60, amazon.com - not bad, but it sounded a bit harsh to my ear.
2. - Seymour Duncan SPB-1 - $65, amazon.com - to me it has the best, most vintage sound.
1. - GFS - $32.95, GuitarFetish.com - sounded almost as good as the SPB-1, and at half the price, it has the best bang for the buck.
Again, strictly my opinion, so take it for what it's worth, but for myself I'd go with the GFS. The Duncan sounds a bit more "vintage", but not so much that I'd pay double the price of a GFS pickup. I've bought GFS pickups in the past, and they're the real deal.