You can't record HD on DVD's. They do not have enough storage capacity to do so. When Blu-Ray or HDdvd comes out, there you go, but not yet. Most DVD recorders will not have a component video in, nor have I seen any that upconvert; doesn't mean they aren't out there, just not very common.

Also the tv guide feature is encoded with the over the air signal and many analog cable systems. Depending on the unit, it works very effectively.