>>3529557If you shoot slide then the best camera is the one you have with you, and buy some AF lenses.
Giving yourself Matrix metering by switching to AF lenses is the only meaningful upgrade you'll find in the Nikon line; the F90X is already a semi pro body. The F100 is just a more modern feeling and looking version of the same.
FM is a terrible idea, if you want to go to a manual camera, go balls deep with an FM3a >(and don't worry about the price, unless you drop it into an abyss there's no way you can overcapitalise on the last and finest manual SLR ever made, they are never getting cheaper)
or an FE.