brown is another 'neutral' color that works with black and white scheme. Would be helpful if you can provide photos or links to the samples you have chosen.

The first thing I would do is switch your light fixture to track lighting. That way you can focus the light onto that wall much like what is done in an art gallery. I also think that may stop the reflection you are getting. I think putting cabinets on the long wall will really close in the space. I would make your red wall your gallery wall. I'd frame everything in white so they "pop" off the wall. The problem with the other wall being the gallery wall is that it's just to narrow. You can't really stand back far enough to see the art.

Warm and welcoming!

I have just bought a schweigen with motor on the roof. The best information and help that I got was from the installers. Parex Industries are the NZ importers, but I must say the only help they gave me was the phone number of the installers. I just tried to find it for you but can't. They are brilliant to talk to and get advise from. I spoke to them before I purchased. The one thing that I realized is the installation is one of the major factors. Give Parex a ring and get installers number will be your best bet, all the retail outlets did was provide conflicting information.