Check out this new LCD monitor form Astro System, the DM-3400.
This mammoth 56 inch LCD display features a resolution of 3840 x 2160, has support for DVI-D (4 channels) and HD-SDI (4 channels/Dual Link).
It also features 4 input channels for a quad display view and has multi-rate support (60p, 60i, 24PsF) and automatic detection of the field (frame) frequency. The HD-SDI input is compliant to ITU-RBT, 1769 and accepts 1-, 4-, or 8-channel inputs. It also offers adjustable brightness, contrast, and chroma levels. Users can also adjust levels for each RGB channel with a remote control. The DM-3400 monitor has one channel of AES/EBU audio with an HD-SDI embedded
It is designed for screening rooms and broadcast studies, so you know it isn’t going to be cheap.