I don't have any monitor advice for you, but I can tell you that there's no current way to get non-Thunderbolt display input into a 2011 iMac and watch it full-screen real-time.
Given the amount of time Thunderbolt has been out, unlikely anything coming that'll do this. Sorry. Too bad Apple doesn't make this easier for folks with limited space and the need to have just one display.
Given the amount of time Thunderbolt has been out, unlikely anything coming that'll do this. Sorry. Too bad Apple doesn't make this easier for folks with limited space and the need to have just one display.