Sorry forgot to add the details:
I am currently using the late 2008 MBP unibody with 4 gigs or RAM.
My scratch Disk is a Lacie 1T connected via firewire 800.
I am currently using premiere pro CS5.
most of my footages are from canon DLSRs (5D and 7D).
i switched from FCP to Premiere pro CS5 because of the native support for DSLRs.
I need a new desktop for my video editing needs. My choice is to get an imac or a PC desktop.
thanks!