Agree with Heo completely. Now in the process of putting the finishing touches on what was originally a 67 Comet Cyclone H-code (upgraded to S-code status) I'm extremely glad that I started with a car that was in one piece and complete -- albeit very rough. I'm by no means a master bodyman, but bolstered by the confidence of a previous build and armed with the Ford/Mercury intermediate body and assembly manuals and a good digital camera to take lots of photos, jumped right in. It turned out to be a MUCH bigger challenge than I ever anticipated and, quite frankly, without the experience of the dissassembly I don't think I would have been able to finish it.
But then again, some folks thrive on complicated jigsaw puzzles.
Another thing, there are nice driver 66-67 FE-powered intermediates that come up for sale/auction from time-to-time, and not usually with Mopar/Chevelle SS/Shelby-crazy prices. On the topic of auctions, and notwithstanding the reality TV and B-J hype, it strikes me that a lot of the concours restoration auction cars end up going for well below the cost of their restoration -- the big clue is when the commentators use that priceless expression "Well bought!" Anyhow, an option potentially worth exploring if you're committed tyo having an FE-powered intermediate.
Good luck!