Save my marriage! Need to split cables but not lose FIOS signal. Odd

Unique situation. I have two coax connections in each room in my house and a 6x8 multiswitch feeding dual-channel DVRs in each room (although my dish only uses 4 inputs on the 6x8). Everything works GREAT.... until you get to the study and living room.

PLOT #1

My study is on one side of a wall, the living room on the other side of the wall. There's one pair of coax running up inside that that wall and a plate on either side - I suppose the builders figured you could put a TV on one side or the other, not both. But I want a TV on both sides. I'd love to put a splitter or multiswitch or some device on either side of the wall to split the two coax cables into four and feed dual tuner DVRs on both sides of wall. But wait...

PLOT #2

I've also got FIOS. The Verizon installer hijacked one of the coax cabels running up this wall, which terminates at a router in my study. The other cable in the wall runs from the multiswitch in the basement to a single-tuner DVR also in my study. So technically, on my 6x8 multiswitch, it's really being used as a 4x7. With me so far?

This works fine for my purposes today. But I'm geting a 55" LCD for my living room on Tuesday, so...

PLOT #3

How do I get my FIOS signal on the same cable run as my DTV signal? Back in the OTA days, I would get a multiplexer/demultiplexer to push an OTA signal on the DTV cable, and then demux it on the back end at the DVR. Can this be done with FIOS? That would solve a problem because then I could get dual channel DVR service in addition to FIOS in my study!

But this still leaves the question of how to split the new dual channel DTV signals into four so I can have a TV on either side of the wall.

Tell me if you need a visual image Man, the wife's gonna kill me when she see's the "surprise" TV and no way to hook it up...

Help save my marriage! Cheers.

-- Seth