If you are moving from those tiny speakers to larger in-wall speakers, then you are going to have a serious difference in audio between the center and the left and right speakers. Your existing tiny left/right speakers would basically go away. I would probably move away from Focal, as I'm not sure the price tag they are asking reflects the performance. But, that's up to you.
To that point, there is nothing about their 8" in-ceiling speaker, at $700 (per speaker?) that makes it seem any better than those from Monoprice...
In-ceiling speaker
www.crutchfield.com
vs.
In‑ceiling speakers are the ideal combination of sound quality and styling. Rather than cluttering the room with large box speakers trailing speaker wires, the speakers are
www.monoprice.com
It would help to have some photos of your room and the space you are putting things into, but I think that if you can't get speakers where they are supposed to go, then don't jam them where they don't work. It isn't better when you intentionally do it wrong. Sometimes rooms just don't support speakers in the right location. It's not the end of the world, but it is something that people sometimes refuse to accept.
So, some photos of the room, and the ceiling, and where things actually go make a big difference. No question though, that I would think that using in-wall speakers in a family room can provide a minimalistic look with much better sound than tiny speakers can hope to deliver.
