Glad you talked to one of the 2 vendors - I think you'll be very happy with that setup.
As far as the PC goes - you may want to have it closer to the screen depending on where the electronics box ends up. Otherwise you have to run multiple long cables to your screen and other input devices (mouse & keyboard, pendant, etc). If you have the pc near the screen its just the cat5e cable back to the electronics box (and maybe the AC power for it). Also makes it easier to plug in USB sticks unless you plan that out in advance too.