Perhaps you should post the speaker question on the "hi fi stereo speakers" forum?
Given the large space, you should look for speakers with a "high" sensitivity rating. I gave a link above that will help you determine SPL given distance, sensitivity and power. The Triangle you mentioned has a sensitivity of 92.5dB/W/m, the Rebel 88dB/W/m. For the same power and distance, the Triangle will yield 4.5dB more SPL. The GoldenEar is 91dB/W/m (3dB more than the Rebel).
Subwoofers can be well hidden, but unless you're into action films, having a subwoofer may not be critical.
Kitchens don't need lots of equipment, only the speakers need to be physically present, and they can be in-wall (or in-ceiling). The rest of the system can utilize your Wifi and be controlled by a smartphone. Perhaps you could take a look at what
Sonos have to offer here (you said the Linn was over budget). The cabled solution with NAD + speakers will also work. As well as the NAD M10 you may wish to consider a NAD C399.
I always wonder when people say their wife won't allow it. I've had no problems finding solutions together with my wife. I do involve her at all stages and consider the aesthetics up front. Our main limiting factor is that we rent, so don't have a free hand for in-wall installations or cabling.
