Have not installed it yet, but I bought the 18 circuit kit from Painless (universal). My understanding is that they are working on an original type replacement for the 67-8.
I think Laurie S has the painless setup in her fastback.
Try our favorite auction site, that is where I got my spare for a decent price. Painless is working on a complete system for '67-68 model years and it is supposed to be available by Q3-Q4 2003. They have the completed setup of '65-66. You could also use there generic 12 or 18 circuit setup.