Re: webcam advice
Your system is old and your broadband isn't that fast, so I don't think you will gain anything by not going for the cheap end of the webcam market and for ten quid or so, they are both surprisingly good and capable.
What I would suggest however, is a headset rather than mic (built in or freestanding) and speakers. That way, you will bypass any potential problems from feedback between those items and the feeling that you are at a 1970s gig by the Who.
Conan