You may be better off looking at a docking station with PCIe cards, or maybe those that go in the wifi pci mini slot (see those things people were using to get external graphics cards on laptops)
Alternatively there are some capture devices that might go in a sensible form factor.
Crazy man alternative if you only want playback and not capture. The screens themselves these days are a sort of common standard a lot of the time. You could then make a fairly simple adapter to take the input from your HDMI (or more likely HDMI to displayport adapter).
Crazy man's bodge it and scarper cousin's alternative. Get a laptop, Lose the screen from it. Get an external monitor of suitable size, power type (many LCD power bricks output similar voltages to laptop power supplies) and with all the types of input you want, mount said monitor on laptop. Wire external video out from laptop to input of external screen. Said external screen will hopefully still keep its conventional selection of inputs.