[richiebee]

Dilemma indeed. Digidesign is way behind on 64 bit compatibility anyway, so maybe a Mac is your best choice at this time. Unfortunately, when 64 bit hits the big time which will happen soon, you might be left somewhat in the dark. Whether that will affect you may well depend on how you use your DAW and whether the spec of the Mac will stress it now. Remember that the iMac is not very upgradable.

Cubase SX will not run on an Intel Mac by the way. Or if it does, it will be unstable. It was never designed to run on an Intel Mac - it pre-dates them. So, if you want to keep using Cubase and you want to go the Mac route, you'll need to upgrade.

I'm curious as to why you want to use Cubase and Protools. You can work with Cubase in the same way as with ProTools (ie, all editing in the main project window) so workflow shouldn't have an impact. Are there features that ProTools gives you that Cubase doesn't?