Re: SPB-1 vs. Fender Original '62 P-Bass
Unless wired in a non-standard manner, all "split" (two coil) Precision Bass pickups are hum-cancelling.
Money no object, I'd go for the Seymour Duncan Antiquity P Bass pickup. My personal favourite active P pickups are the Basslines APB-2 Lightnin' Rods and the long-discontinued Active EQ series for P Bass with the tone modifying DIP switches.