I think with the restriction of only a foot or so off the back wall that a smaller stand mounted speaker like a Proac D2 , or even a D1 will work out better..placing a speaker that close to the rear wall in addition to diminishing sound stage depth ( can't create depth if there isn't any) having a speaker that close to the rear wall is going emphasize bass response in a bad way, so if you get a larger speaker that can really do bass I'm afraid you'll end up with a boomy, muddy lower end, that can also effect the mid bass and even lower midrange. Frankly even the D2 may have to much bottom end that close to a rear wall and the D18 certainly will have to much bottom end. I think maybe the D1 or even the new Tablette Anniversary with a GOOD sub maybe the ticket.. There is a recent review of the Anniversary in a recent issue of Stereophille.. nice thing about either D1 or Anniversary is that they are small, so the wife will be happy, they throw a BIG sound stage, and because they're small you can probably cheat a bit and get them further out into the room than a visually larger speaker ( just don't cheese out on stands)
As for a sub, with a speaker that's as quick in the bottom end as a Proac the only real choice IMHO is a REL either a R-328 or a R-218 which one would depend on room size, budget and how loud you want the sub to play, nice thing with a REL is that you can set it up so it doesn't effect the quality of the bass, nor will it effect the performance of the main speakers in anything but a positive way.