OK. Thanks for the reply.

So what I understood from you is that if I'm downloading the 10.5.6 of iPC I'll be able to dual boot easily w/o additional software.

I'm downloading the iPC (as we speak...) - but it's a (+live) version of 6.5 gigs. My CD burner can only burn single layers, so I guess I'll have to put the iso file on disk-on-key (USB) or external HD.
In that case, what has to be done? is that straightforward as DVD installation? Are there adaptations that have to be done? Other than maybe changing the BIOS to boot primarily from USB/external HD

Thanks,
Josh.