How can I retain my HD quality from a camcorder in live streaming? Also - any camera/converter suggestions?

Currently we use Adobe Connect to stream and record live events that go on in our office (panelists, speakers, etc.) This is not very interactive - we do not receive video from the viewers, we only broadcast the presentation and post it online. The quality of our webcam is very poor, and we would like to get an HD video camcorder that will give a better picture. However, in my research I have found that in order to ensure the HD picture is retained in the streaming, I need to set up a converter or encoder of some kind that does something to make sure the bandwith can handle the HD picture. I am very new to this and I am having a hard time figuring out what exactly I need. If anyone can help me out and inform me of what setup you use (camera too - would love to know suggestions for the best cameras that work with Connect) it would be much appreciated. Thank you!