Very cool '71! I love the seats. My '71 has leather seats but I'd take the cloth insert seats over leather any time!
For wiring harnesses, go with M&H. They are sold by Year One and by Megaparts. You can get up to 30% off with discount codes from YO, but I'd still opt for Megaparts over YO because of their great customer service if I had it to do over again. Sometimes these wiring harnesses are on back order, and YO will just leave you hanging for months until they finally get them and ship. Megaparts I'm sure would keep you up to speed what's going on.
I used M&H on my T/A project, and the trunk harness took 3 months before I received, the headlight harness came right away, purchased from YO.
Worth the wait as these harnesses are great.
I used Fine Lines fuel and brake lines and no complaints.