Thanks for all the help everyone. I've decided to keep the Mitsu and DTC100 together, and running one strand of RG6 upstairs, with Toslink to coax converters connecting it to the Marantz. This is easier and cheaper that running 5 lines of coax for going VGA to BNC between rooms, and in existing walls it's going to be a bear anyway. One strand is enough. I'll be sure to pull 2 pair of CAT5 at the same time for future proofing.

BTW, my wife thinks I'm whacked out of my gourd. There's a bundle of cables as thick as my skull running through a corner the garage now. Wait until she sees me pulling more through!

Thanks again!

Patrick Fern