Ironically, you are talking about two of the models that I have had the least listening experience with, but I'm very familiar with the Focal Chorus 700 and 800 series speakers.
The hi fi store that I deal with generally carries the 706v, 816v & 836v speakers and currently has 806v and 807v speakers as well. I own the 836v speakers, but almost went with the 816v speakers. The reason that I opted for the 836v was that I was planning to go without a subwoofer (I've since added one for home theater) and there was one particular song that I heard in the store where a background harp sounded like it was in the room on the 836v and just didn't have the seperation on the 816v.
I purchased my father-in-law a set of 706v speakers because it was at the right price point for the purchase and he chose Focal over PSB, Paradigm, B&W and a couple of others.
Just last week a friend of mine purchased a pair of 807v speakers and I really like them as well.
The 800 series speakers have thicker cabinets and more internal bracing so there is less resonance and the 800 series floorstanding models have a bottom firing port that give the low end bass a boost. I've only heard the 726v once in a different store and it was on much less expensive equipment but wasn't nearly as impressed.
I can tell you that the 806v sounded better to me than the 706v in the same room and nearly identical gear.
If you're planning to use a subwoofer for home theater then I'd recommend the 816v that retails for about $2,000. Like the 826v it is a 2-1/2 way design and I suspect the 3-way design of the 836v is partly responsible for the improvement in instrument seperation.
If you want to maximize for 2 channel, I'd find a way to get the 836v speakers. I absolutely love mine. I could be very happy with some of the other brands that I've heard, but I really like the Focal tweeter. I think it's head and shoulders above the rest, but I know some people don't like it at all.