Since the DEC VT100 was the gold standard for serial terminals in the early years, that's what I will base my design on, and since it will be a driver for a 2:3 scale PDP-8I I'll scale my design accordingly.

I will not be making a true replica VT100. The plan in fact is not even to make a real serial terminal. I want to make something that is clearly a VT100 derivative as close as possible in look, but sourced with modern components. So for instance it will have an LCD screen disguised as a CRT, and the 2:3 scale precludes having a full sized keyboard with number pad like the original.  The display will be hooked directly via HDMI to the Raspberry Pi running the PDP software, and the keyboard will be USB connected to the Pi as well.