Let the hive mind of Engadget get that for you.
"I've found myself using my PC for a lot of conversations lately, and I'm also considering recording a podcast to share with anyone who will listen. There are tons of USB headset / microphones out there, and I'm hoping someone has some solid recommendations based on experience. I'll consider both headsets and standalone mics, by the way, but I'd like to keep the bill under $100 if possible. Help!"
Many people don't even notice a difference between 2Mbps and 10 Mbps.
If you really want a true HD experience then "just" buy an HD disc which will get you 1080p @ a bitrate of +- 12Mps combined with a true HD 1080 screen and a nice surround set you'll be in bliss.