I believe the wheel speed sensor is integrated in to the hub assembly.
If you are not having any other issues with the rear hubs, I would recommend ruling out the wiring harness before throwing hubs at it, mainly to avoid the "lets throw parts at it and hope it works" factor.
Also keep in mind too that the 2000+ Gen loves to crap hubs, so if you haven't checked them for actual bearing issues, you should. If it'* crapping the hubs/bearings, replace them. Also, there is data on the forums to guide you which brand to get, and I can't remember which brands to avoid.