Does anyone have an affordable (read: sub-$2,000) DDR solution for simultaneously recording and playing an HD stream? I'm thinking something like a Tivo but for professional video. I see a lot of very expensive decks out there from Fast Forward Video and others, but I can't afford anything in that price range.

A Tivo would almost work for me, in fact I've used an SD Tivo for this same purpose in the past, but I'm now stepping up to live HD production and there are some times when we want to be able to delay playback for overflow purposes. The biggest problem with the HD Tivos (other than the possibility that the audience would see the control bar when I start the playback) is that they only accept an antenna input - no HDMI (I understand that it's not supposed to be recorded according to the spec.) or even component analog HD inputs.

Any suggestions? I'd even be willing to use a computer system for this if there's software that will capture and simultaneously play back what's being recorded.

Thanks.