We have a 2012 Silverback with one AC in the middle, and its wired for a second in the front bedroom. I just purchased a second AC to install in the front...which I hope to do sometime in May (due to weather here).
Mine is wired with power only, and no thermostat wires, but has the option to tie into the ducts. I want this second AC tied into the current duct system, which requires a certain ceiling assembly, which does not have thermostat controls. Therefore I will have to figure out a way to get the thermostat wires to a wall location.
I guess to better answer your question, you should remove the trim-work that is in the vent location now. Should jut be four screws. Take that down, and you will see if you have power, stat wires, and if the ducts are there to tie into.
Good luck!