Interesting thread.
I had a similar problem (and still do to some extent) where finding a rack proved more difficult than deciding which equipment to buy. The problem is, I think, that A/V rack manufacturers expect most customers to own style systems, so generally don't offer racks with enough shelf height/depth to accomodate full sized centre speakers while allowing a receiver room to breathe.
I'm sure if someone produced a cost effective and attractive rack with about 30 cm headroom on the lower shelf and 22 cm on the upper shelf, with a depth of roughly 45 cm, it would sell extremely well.
After extensive searches the best I could come up with for my needs was a relatively tacky glass stand, which just about houses my kit, but I'd love more shelf height (my receiver probably has roughly 4-5 cm space at the top, which is far from ideal). In my quest to resolve my problem I've started contemplating building my own, because, try as I might, I can't find a rack that appeals aesthetically and will house my kit satisfactorily.
It's either that or go the expensive custom design route.
Little help to anyone, I appreciate, just venting my frustrations on the same topic.