Der Rot Konig:
Ok, I'll try to expand a tad, if it helps.
The players would not be gifted heroes in any sense. Yes there may be a police officer or soldier but the characters will essentially be just regular, everyday people facing rather steep opposition. I want them to have a wide range of skills, etc. to draw upon.
Also, it would help if the system was rather popular. Finding players can be rough sometimes, no matter how fun or good a system is.
Since I don't play it any more, it would be almost useless to parrot the notion that GURPS is one of the best systems I've ever seen
for this and the other requirements you listed period. I only quit playing it due to lack of forum support that wasn't a direct attempt at a cash grab. I won't go into detail here since it's off topic.
So with that being said, Modern AGE system has a good variety of Professions, Backgrounds, and Drives that come together to form their characters, and while the variety is less significant than GURPS, the game is also less complicated than GURPS.
Modern AGE is also fairly compatible with previous games in the system, Dragon AGE, Fantasy AGE, and Titansgrave: Ashes of Valkana.