The p2p stuff is good. If you're willing to pay you can get HD feeds online with NFL Gamepass, and near HD NHL feeds with ESPN360. The NFL is surprise, surprise, pretty expensive, whereas ESPN360 is pretty good value IMO. But I guess you'd probably need an out of US credit card/billing address.
For the Bills - www.nfl.com/gamepass
For the Sabres - www.espn360.com