How about mounting them lower (so as to please your wife), but then angling the speakers a little bit, so that the side firing tweeters on the inside are aimed a little above teh listening area? The speakers on the other side will fire a little down a bit (they'll be firing away from you anyway in your set-up - so all that you'd hear from them is the refracted soudn to begin with). The woofers on teh top and bottom will still be firing up and down, but again at an angle. This may make the sound appear to come from a little higher than it actually is.
I don't know how mounting them will go. You'd have to be careful not to angel them too much so that they don't fall off the mounts - but I would think that the speakers woudl be heavy enough to stay put.
