Turning my 27" iMac into an ultimate Windows 8 PC

With the arrival of Windows 8 I'm thinking of switching to the world of Metro (Sorry MS, we'll call it Metro anyway). I'm thinking of adding one of those touch screen overlays and installing Windows 8 as a primary OS. I've heratd that Windows 8 works just fine on 27" iMac (i have i7, 4GB RAM, 1TB HDD, some decent ATI graphics, etc). Does it sound crazy? Touch may not be a primary interface with a desktop but I feel it might be a nice addition as long as the OS is touch-friendly. Does anyone have any experience with touch screen overlays? Can you recommend one to convice me against it? Thanks!