are you dealing with an 87? i assume so because of your sig. that stated your switch is different from mine and all other pre-1987's.
the seat track is identical. the switch in the pre-87's as back as far as 85' anyway is also the same. it is just mounted differently.
i still have the bench seat and track setup and i can take some pictures for you so you can see how GM did the install.
finding a power seat setup can be difficult as no salvage yards seem to keep any g bodies on hand. i believe that 78-87 monte carlo, cutlass and regal will have what you need. in addition i have heard that the cadillac cimmaron has the same power seat track also, i have not seen this myself though. check ebay.
what you will have to be concious of is the switch and wiring harness you acquire. if your wiring harness is from an 87' you need a 87' switch unless you plan on cutting and splicing wires.
i have a full 1986' power seat setup right now. all it needs is a switch but i might have one on the way. i would sell you my setup but not until i recieve the switch and test everything.