Hi I'm about to purchase a 27" iMac - 3.4ghz i7 ssd + 2tb & 2gb gfx. I already have a spare 23" Cinema Display (aluminium frame) from my old system. Will I be able to run this as a second monitor with the iMac? If so, what connecting cable or plug adadptors will I need to buy from Apple? Many thanks for any info.