Some very good suggestions here, and given the diversity of interests (WW2 v cold war... and what about WWI :P), an approach akin to X-Plane or similar which is more modular would be the way forward - however this runs the risk of becoming generic I suppose.
Either way I wholly support a community project whatever its form, and would be happy to contribute in whatever way that I can. As long as there is support for multiple monitors showing multiple interfaces I will be a very happy chap