You also can drop the appearance extension that comes with 8.1 into 7.6. That will work too. I recommend against using Aaron with these better alternatives.
Actually I've just realized that I need system 8 for Deus Ex (not that it's what I'm buying this machine for [] ]'> ) I'm also going to put in my Radeon Mac Edition (instead of the 128) from my G4 server as it's not getting used much.
Radeon Mac Edition is probably the single best possible card for 7.6 or 8.1; hardware T+L but without the driver issues of the Radeon 9200 series boards.