This thread isn't so much about how to build a particular character, but rather how to put together a tight group. These are some of my thoughts on what every group needs to cover to be successful at running the shadows.
1- A matrix specialist. Absolutly mandatory. Technology is everywhere. You might get by without a magician, or a drone expert, but the net touches aboslutly everything. You need a top line hacker, somone to spoof the security systems, to open the maglocks, to gather (and plant) info. The web is just so ubiquitious that it would be hard to get buy without someone watching the matrix for you.
2-Some basic social skills. Every group may not need a full blown "Face", but someone should have at least a moderate charisma, some etiquette, and some negotiation. If everyone is an uncouth cyber-muderer with a charisma of 1 and no social skills you can't even get through the meeting with Mr. Johnson, let alone handle situations where you can't just shoot everyone in the room.
3- The ability to do legwork. You can't lay it all on the hacker. Everyone should have several contacts, and several knowledge skills that are potentially usefull for background, investigation, and general information gathering. Coordinate and diversity. The group should cover as many areas of knowledge and as diverse a group of contacts as possible.
4- Solid combat bonifides. While some groups end up all gun bunnies and vat grown ninjas, the opposite can happen as well. If you sit down at the table to find out that you have a street doc, an hacker with combat paralysis, a shaman with no combat spells, and a non-magical, non-agumented detective with no combat skills above 3 you are going to have a bad time once the lead starts flying.