I've always liked the sound of wooden support furniture for hi-fi, as long as it's oak, and well made, so second Colin's recommendation for Hi-Fi Racks.

The only thing I've found which is better is Russ Andrews Torlyte. It comes in standard sizes but is built to order so they can customise. Standard Hi-Fi racks, or AV racks. If you go for the standard hi-fi rack, get them to make it a little wider/deeper for 800 series gear, or ask for a 4 pillar version (the third pillar at the back is difficult for some cables). The AV rack should be fine though.

Contrary to its appearance, it is very much not solid wood, but a torsion box of extremely light wood, you'd be astonished if you actually pick up a whole shelf, easily, with your little finger, yet it's extraordinarily rigid and almost completely free of resonance. Very clever engineering. Can be stained black if you don't like the wood finish.

They now use curved corners and oak uprights, but I use and prefer the older design with box/rectangular square cornered Torlyte uprights also, both aesthetically and SQ, which they can still custom-make.