if you go to www.emulation.net
(a great mac-only emu site
)and look in the Amiga section you can download the beta 3 version of MaxUAE. Even though it's a beta I've found it to be much better than MacUAE 0.8.6 (which I believe was the last version before the project was canned).
It *sort of* has AGA support but everything is tinted green for some bizzare reason...I'm keeping a look out for beta 4