Ok here is my scenario... I have the 21.5" 2011 iMac. I'm wanting to do a dual-monitor setup. I found a LED monitor for a good deal. My question is, can I hook it up via HDMI with a Mini Display port to HDMI adaptor? Or must I have a Thunderbolt to HDMI? I know Thunderbolt is backwards compatible but I'm just unsure as to how it works with video. If the Mini Display adaptor will work, will the picture look fine? Its a 1080p monitor. Thanks for any help!