well thomasb
Had some flashes going of in my head when i seen your ready made space, and the more i thought of them i thought they would look great in my house , except i don't have a space like that and anyway my cinema is going to be portable. But that's another story so here goes.
Build a frame work of either 20mm-30mm box section steel or 50mm wood.
This would be split when looking at it middle half and a quarter either side, hope your with me. Now either side quarter would just be stretched material over the frame that your speakers would sit behind and the middle have sheet wood. The middle section would have the screen mounted flush with picture frame around it and sections cut out for shelves for the gear.
Also if you leave the rear of the shelves open but again covered with material you could have led lights mounted on the back wall which would glow through the material, or just mount lights in the shelves.
But the main thing about the frame is that although it looked like a middle section and a section either side it would in fact be able to spit 1/4 - 3/4 and either side would be hinged to allow you to swing the frame open like big doors so when ever anything fails or you want to change anything or alter something you just pull on the hidden handle and the frame opens up to allow you to do things without having dismantle or disconnect things. Or have the side panels only material where your speakers are and the rest shelves, but again have the shelves actually mounted on the back wall so the frame is not carrying there weight if you want the frame to open.
ramble over
