Tecumseh:
I'd be especially interested to hear more about Nu_Fenix's experience playing this with Shadowrun. That is the setting I am most familiar with, and I'd be curious what worked and what didn't.
I can't remember much, as it was several years ago. We had a group played as, but also had a figurehead. The figurehead had a bonus to an action of our choice, which could be attacking, negotiating, spying, hacking, etc. You had so many points of different resources to spend each turn, which could be used to improve what you had by buying property, recruiting people, and so on.
As far as I could tell, it was a completely homebrewed system the GM made.
Also, replying to allow a bump, to find more potential players, but primarily a GM who would be interested in doing such a thing.