Web cams, USB Extension cables and Digital video cameras on Firewire

My first question was answered but now I’m on to my second one, which has become challenging. In the office, I have an iMac 27" and I have two logitech C930 cameras. They work perfectly fine and are both on separate busses. However, that short cable is not going to work as we needed to put the cameras up near a podium, on tripods, so that the speaker could be seen. I purchased an 82 foot USB2.0 extension cable that boosts the USB signal along with the power adapter so that the computer did not have to power the camera through that long cable. But as soon as I hook them up I get nothing but static and the note saying the previous camera is missing. At this point, I’m at a loss as to how to do this since we don’t have many other way to our the presenter on camera during this internal business conference.

The second part is we may have a digital video camera that would work with a firewire output (I think). I won’t see the camera until Tuesday. But I’m not sure what the max length of a firewire cable is and how to use that to reach the control table in the back of the room about 50-60 feet away. Does anyone have any suggestions on how to use these web cams and what I can do? Or is there a wireless web cam that is HD and works with a mac that might work for us? And I have not idea how to make a camera connected by firewire work with the mac or boinx tv as I’ve not tried it yet.