Is it possible to run a hybrid MAC/PC network off the same MAC based filemaker server 10 installation.
Yes, the same files generally work on both machines.
Select fonts that are installed on all machines, plain vanilla fonts are less trouble. You'll probably find that you have to tweak a layout here and there as windows machines require a bit more room to display the same block of text. You'll also want to double check your printing processes to make sure they work equally well.