You guys are looking at some pretty cheap webhosts... and by cheap, I mean cheap. Even if they may offer hundreds of mbs, and gbs, they might not be able to keep up with demand.. or have crappy support, or could take your money and run.
For discussion on webhosts, and to look for competiting bids, check out
http://www.webhostingtalk.com/
We use
http://www.Krellen.com/ for our website: CogSquad.org and I use
http://www.alwayswebhosting.com/ for my personal sites.