3rd Monitor Choice / Audio for Picture

[belasoul]

ATM i use a Mac Pro 6.1 with a D-300/12core/64Ram and two thunderbolt displays for mostly soundediting.
I would like to upgrade the setup and get a third monitor to showing the picture. I tested a directly hdmi connected panasonic tv which seemed to work quite smoothly, even though i'm using a feature length h.264 (in full quality mode).

What would you recommend from your long term experience, when it comes performance in bigger sessions and video stability. Would you recommend an external video hardware right away or would stay with the mentioned setup for now? If yes, what specific video hardware would suggest combined with a trashcan?

Also are there any specific TVs/Monitors which can be recommended? I'm thinking about getting a Samsung Frame, just because it is very flat and would save some studio space.