buy wire, period correct tape and a couple of sheets of plywood There are none to be bought. If you want a new harness it's going to be you building it.
www.wiringharness.com (M&H) at one time claimed they will build one for any car based on the factory wiring diagram.
The harness is not for myself. I had recommended M & H. I bought one of theirs for my Belair. extremely happy with it.