Gonna echo the other recommendations for the EOS 3. If you enjoy using your 5D, the 3 is probably the closest film equivalent. It'll work with all your lenses and flashes which is super convenient. Build quality is quite good, AF is fast and accurate (eye controlled focus doesn't cooperate with my glasses so I just leave it turned off), and battery life is pretty good. It is on the larger side but it's comfortable to hold, lighter than your 5D with similar ergonomics. You can find them regularly for $150-200. The 1V is nice but I don't think its worth the $300+ premium over the 3, especially for portrait work.
The F100 is a great camera, but autofocus isn't comparable to the EOS 3 and it doesn't make much economical sense to use an additional lens and flash system.
The F100 is a great camera, but autofocus isn't comparable to the EOS 3 and it doesn't make much economical sense to use an additional lens and flash system.