OUCH, $150 for a a used 15 year old seat? I got both of mine for $70, mine where light saddle leather, with bolster, and lumbar, full power, got the seat belts, track, and everything.
Back on Topic though,all the seat needs is a positive, and a ground wire. That's it, all the control,is in the seat it's self. I am uncertain, but I am fairly sure that the wires you are talking about are for the seat belt light. You will need to run your own 12, or 10 gauge wire for positive, and make sure it is fused, you can run your own for the negative, but I think you can get away with doing a short run with a wire, and using a self taper onto some sanded off sheet metal. You can also get some plugs from Autozone, advanced, but the best ones I found where at my Local Ace Hardware, they are weather pack plugs meant for trailers, and I believe they are 12 gauge. You will have to do this since you do not have the actual plug from the factory, or you can just cut the plug at the floor at the junk yard, and splice your own wires in. It is up to you really. Good luck, it really isn't that hard, unless you are like me and want everything to be perfect...