I have the 2.5 Black Magic Cinema Camera, and I've been researching possible monitors to purchase.
I believe my best route would be to buy an HDMI Monitor + Converter, as opposed to an HDMI/SDI Monitor (quite expensive) - my budget is around five-hundred dollars.
I want something that is portable for run-and-gun shoos (documentaries, etc.) - my other issues are the glare of the monitor, and getting accurate color representation on the monitor (as the camera screen color is very flat).
SmallHD has very good monitors. The ac7 starts around $600. BM has their new Video Assist which has a 5" 1920x1080 monitor built in for $500. You don't need the recorder, although, you could use it to record proxy or backup files. Marshall also makes decent monitors.