I use SimPE in a virtualPC environment, and with a little workaround it is perfectly satisfying; plus there is a mac project very interesting: WooHoo (
http://woohooformac.wordpress.com/) which could became a very power tool.
The worst problems that I found, and I'm not yet been able to resolve, are with programs that check default Win installations of the game prior to start. I tried to create a fake installation on my virtual disk, copying files, but it didn't work.
These programs are essentially TS2enhancer and a few others.
Consider, anyway, that I own a G5 mac, while now Macs are Intel-based, with better, if not full, win compatibility (you can install _natively_ both MacOSX and Win on the same machine).