Shnakz,
We have done a few also.
SWM switch placed at the dish. One RG6 to a high frequency 1x8 splitter. Yes, splitter! One RG6 for remote power.
If you are using a new HD-DVR I am almost positive that you only need one cable to that box. I could be wrong here.
Yes, three legacy ports.
Also, remember the b-band converter is not required.