Editor 100

I have a late 2013 Mac Pro running Adobe PP with two unused thunderbolt ports. The graphics card is a AMD FirePro D500 with two slots supporting the existing two screens. I need to install a third edit screen which will need a breakout box, something like a Blackmagic UltraStudio. Does anyone have any suggestions of the best way to do this? Also does anyone know of an engineer in Southwest London that could support me on a three month edit?