As far a bandwith goes, you shouldn't have any problem viewing outside videos (I can watch cable TV (no HD) with no problem at all and good image quality with that kind of bandwith).
What might be an issue is the UP speed. With only 16-20 KB/s you might be able to send a 320x240 feed that will be pixelated but still very discenable.
A good webcam (a good whatever in fact) is one that can cover your needs. So my next question is what do you intend to do with it? How important is video quality and sound quality? A resolution of 320x240 should more than enough for most people, it won't be impressive, but you should be able to work-out fine details if the bandwith is suffiscient. As for sound, if you want good quality, I suggest you get a seperate headset unit or at least a microphone. Otherwise, what is built-in does the job, but don't expect much from it.
As far as actual webcam hardware goes, I don't know much. I noticed many people complaining about logitech drivers for the webcam so you might want to consider another option (like Microsoft or Creative). You could also get a Logitech in a store near you, try it out, return it and get a refund and the buy the one on NewEgg.