Do I need a Blackmagic Design Multibridge Pro just to edit 2K (2048x1556 @ 25fps) in 10bit RGB 4:4:4 (or sometimes even) better in Vegas?

Currently I don't need the HDMI- or HD-SDI i/o but I would like to display 10bit colors on a display.

Does video playback nicely on a top-range GeForce based card in combination with a calibrated dual-DVI monitor?

Would you advise to install a second multi-CPU environment with SLI - would Vegas benefit from this?
Would CUDA be helpful?

I'm going to build a new PC so I can use suggestions.