I'd go for an F4 if it was me - had a handle of an F90x once and put it down. The F4 has controls simply to hand (speed dial on top, aperture on lens, iso speed dial etc. plus a sync socket on the front and it takes normal batteries)

Haven't tried an F100 but I guess that would be a good choice as well for lenses without the aperture ring (and of it's anything like the D1x is it should be easy to use)