Thanks again Steve. Yes, Genie + clients would work, but I think then I would be paying for 4 additional TVs with DirecTV, no? And I would need set-top boxes everywhere.
I would actually even prefer to have 2 TVs on Genie and the rest plain OTA with no DirecTV at all. I don't want to pay DirecTV PER TV - that's why I installed DirecTV years ago and bought all my own equipment.
So I'm really still looking for a diplexer that works with HD satellite feeds so I can use my existing coax lines for sat or OTA or both depending on the room.
EDIT: the answer might be this!