What should i be looking for in a good pc?

well i don't see how you can build your own mac :p
and...Cubase for Linux?/Open source/win?

That would be one reason why I didn't say "Build your own, regardless of OS preference".

Ardour 2 can be built with VST support, so in principle you could get a GNU/Linux recording setup if your devices were supported. Unfortunately, bazillions of common devices *aren't* supported, so you're stuck with interfaces made by companies that don't consider themselves too cool to write another driver... but if your devices work, it could theoretically be done. (I'd say more, but I haven't recorded much lately and don't exactly know the current state of things myself.)

TheWinterSnow... a few years back nobody had dual-core support, but people bought dual-core anyway for the few programs that had support and the comfort in having a slightly more 'futureproof' system. Some applications today can use quad, and even those that don't can benefit from not having other processes trying to compete for time. If the price difference is acceptable, go for it... we'll be seeing support for these things soon (plenty of programs, anywhere from scientific computing to other multimedia editing, already have support for 4+ cores) and for the slight difference in price there's hardly any reason to stunt the system that much.

Jeff
 
Okay so im now considering a mac....How powerful a mac will i need to run cubase 5? And will i have any problems using my firepod with a mac? Will they have the TI firewire?

And to clear it up...This comuputer will be used for audio and nothing else, no connection to the internet, nothing.

Im in australia, is there a place i should go to suss the macs or will any shop do?
 
The real bottleneck will probably be the plugins, not Cubase 5 itself. You're looking for a good chunk of RAM, and since (as far as I know) any Mac you'll be looking at will have decent multi-core processors, that's not too much to worry about. Unless you're dead-set on a laptop, a modern iMac or high-end Mini should do enough (unless you're running about three metric fucktons of plugins, somehow...) - looking at refurbished devices is probably a very good idea, too.

Jeff