I can't believe that I am being sucked into this. However, here goes
1) PVR is right. There is no way that you could stream anything but one channel.
2) The fact the D* tends to compress the heck out of the streams sadly doesn't even help you.
3) 802.11b is a tricky beast that tends to get interference from everything. It is hardly a robust thing.
4) You *would* need to take an analog stream and convert it to a digtal stream. (I think that 2.5Mb is a safe ballpark range)
5) You would need to control the box at the other end. (i.e. You would need to dictate the source going into the encoder)
6) You would need to take the mpeg stream and translate it to NTSC.
7) and a couple of other hurdles
The only easy to use solution that could be possible would be the 2 replay4000s. Even then you would have to go to your parents house to program their replay4000.
However, if you could get it to work, it would be pretty cool
-Steve