Also, I don't know if this is a factor or not, but most of the channels I want
to record are digital cable (that includes BBC America, Sci-Fi and many
others). I don't know if Myth TV or any other homebrew system handles
digital cable signals.
Many HDTV capable tuners can also handle digital cable. The
problem is that many if not most digital cable channels are encrypted
so even if you can tune them it doesn't do you any good.