I use an EOS 7e for film, 10D for digital. I love both, although I haven't used the Elan in a while...
Do I like Canon better than Nikon? Yes, because when I started putting the system together, Canon's "workflow" made the most sense to me. However, Nikon glass (which you will acquire eventually) is compatible with the excellent Fuji S-series digital SLRs and the Kodak ones; Nikon is simply a more expansive, friendlier system.
So on that note, an F100 is a fine, durable camera (I believe Fuji dSLRs are built off this platform).
I have played with the N80 and didn't like the feel, although a grip may have solved that problem.
The F5 is quite a piece of work; I believe it is the only film body to use the 3d Color Matrix metering(?) But as others have said, it may be overkill.
Bottom line, I'm leaning towards the F100 for you. Its a good balance of features and practicality. Remember, its not the body, so much as the glass in front of it. AND, its not the glass in front of it, so much as the brain behind it!
Didn't mean to turn this into a Canon vs. Nikon debate. But if I did, I played fair right?? -Austin