Making the best of mediocre speakers

I want to get the best system I can, given unfortunate constraints. I'm building a new 2-channel listening system in a new apartment, and my wife insists the speakers in our 17x23 living-room must be in-walls. They fit into a particular lowered soffit, so they'll be installed just above head height. The Sonance Z4s are the best I could find to fit the area; they're OK, but obviously this is a compromise.

So I am planning on a nice subwoofer (which, btw, must also be in-wall), maybe by James, to beef things up. Then about 3K for separates--I am considering a Rowland 102 amp, a Rogue Audio Perseus preamp, and a Cambridge or NAD CD.

My question is, am I wasting money, given the in-wall speakers and placement? Do a nice sub and electronics make up for the speakers? Or should I throw in the towel and just get an Arcam Solo or something?

Many thanks.