The largest problem he faces in making it realistic is that General Atomics closely guards all its information. So, even simple things like how the HUD looks is restricted by the manufacturer.
Ultimately, the best thing to do is superimpose a standard military spec HUD display in green tint over top the view of the ground, and then have the view of the ground be linked to basic joystick controls so that there would be a way to map its ability to zoom in/out, and pan around, while at the same time assigning the primary joystick controls to normal pilot functions. The challenge for the gaming PC pilot would be to keep the aircraft flying properly while looking down at a small piece of ground while relying merely on the HUD instrumentation to keep proper alignment.
In other words, a lot like flying on instruments while in IMC, except you have the distraction of watching a small piece of the ground you look at. Go with a single standard radio using the default FSX interface (which itself is limited to just VHF). And remember, there is no automated system for takeoff and landing. It's pure manual pilot stuff, and it isn't easy!
Unfortunately, the more interesting elements could never be replicated. But, it would be a lot of challenging fun if they could.
Ken