Keith
I have both F6 and F100 so I can compare and relate to both.
Short answer: get the F6
long answer: F100 has a somehow more "impressive" autofocus (it's noisier yet it gives you the impression of a dragster) while the F6 is silk smooth.
While you can find 1 million F100 around the world, F6 is a camera for life.
First, it fits my hands better than any else F or D I ever had, D700 included which has already a great handgrip. Second, it's versatile like a D-SLR with its menu (and possibility to save shooting data for many and many rolls, define non-cpu lens data etc) and - at least imho - AF points are just fine. I've never seconded the latest Nikon trend with more and more AF points whose more powerful are anyway and always in the centre. Nikon - flood aside - should keep in mind basics first, as my old teacher said. Basic, first, then and only then, "fronzoli" (bells and whistles).
I'm sure you will enjoy your F6 for many years to come. Get it.
If you were in Italy, I could suggest you one of the most reputed sellers over here which often have a F6 (here sells for much less than there, the latest one was 880€ while an F5 sells for 300/350, an F100 from 200 to 300 and a FM3A for 350/400)
That said, F100 is the second camera I'd get (again, money-wise) after the F6...