I think from memory there was an issue of unstable performance after 60 minutes.... But one of the software guys may be able to clarify that. How about a string of 12 TiVo's all with an hour bufferhack :P
Regarding having a valid video input: Yes. The TiVo will need this and yes anything will do. I once used a TiVo to record a marathon radio special and it worked perfectly with the video input from a VCR.
Cheers
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