Kenny,
I say the RCA HDTV DSS system at Best Buys last weekend for $649. They were still fiddling with it trying to get it to work.
Check it out throughly as I don't think it is compatable with the Mitsu HD inputs you have and I was told by the salesman that this DSS HD receiver is only compatable with RCA and I would assume ProScan. Seems like everyone is working in a vacuum.