The site I plan to host will bring with it a huge share of followers. I ALWAYS go over my Bandwith. Does hostony have a way of letting us cap our bandwith, say, if my bandwidth is 65GB, is it possible to "shut down" the site once it hits 64GB, or perhaps have it automatically redirect to a non-bandwith-intensive page?

Yes we can setup to automatically shut down your site if bandwidth is excedded.