Thank you for mentioning Realmz. I played a demo sometime around '97 and have been recently been hoping to find it again, but could never remember the name of the game or developer. I'm glad my search is finally over - looks like one of my projects for this weekend will be finding an OS 9 emulator.
Your best bets are SheepShaver and BasiliskII. The former for emulating PPC Macs and the latter for 68k. The best resource for setting these things up is the e-maculation wiki and discussion forums [1].
