I have a white Dimarzio Pro Track single coil with plenty of lead left. $45 shipped. Here is the description of the pickup.
It sounds like a vintage humbucker and will drop right into your Stratocaster. The Pro Track has enough power for any pickup position, and the 2 blades mean there won't be any problems with string alignment or dropouts. In the bridge position, this is a great blues pickup: combine it with a Cruiser (neck) and a Fast Track 1 (middle) for a solid mix. Pair 2 Pro Tracks in the neck and middle positions with a Fast Track 2 by the bridge for a heavy, yet versatile metal sound. Recommended for all positions. Output: 275mV.