I'm thinking about getting a 7 or 8sp internal hub and I'm wondering if my exisiting canti brake levers are going to work with either a drum or roller brake. Anyone care to convince me why I should choose one over the other?

As an aside, if I could use my 7sp thumb shifters to run the Nexus 7, then I'll definitely get a 7sp nexus... but as far as I know that won't work-- please correct me if I'm wrong! I'm thinking 7 or 8 internal rear, with a rear derailleur for tension and chain take-up with the front triple (48-24) Any problems with that?

Thanks for the help!