I really need to take some time to look through the garage and see what all I have on hand sometime. I have a LOT of MKIII gaskets boxed up somewhere.
You'll find an online version of the Toyota Electronics Parts Catalog here:
http://www.cygnusx1.net/Supra/Library/EPC/ It might take a little playing around with for you to get the hang of it but everything you need is there and if you get stuck on one post a link and the reference number and we'll get you squared away.
Replacement connectors/pig tails used to be available through the dealer. I'd go that route over putting in old brittle connectors. Or convert to GM weather proof connectors from NAPA.