I did a similar install to what you describe in my old Tacoma (FT7800), and I'm also running my FT7900 in the center overhead area in my 80. I'll have to see if I have any pictures of either install. I ran the main wire for the faceplate as well as the mic wire into the headliner, over to the A pillar and down behind the dash. They sell long, 6 pin phone wire (~25' IIRC) and couplers at Ace Hardware for extending your mic that distance from the faceplate.
1976 FJ40 - green and mostly stock
1996 FZJ80 - not so stock