Where to find?
My builds are usually p2p tube ones with everything mounted on the front and back panel, so the deep cases available are a bit annoying. Something 15-20 cm deep would be nice.
Doesn't look bad! However, they have their own way of mounting the front panel, which makes getting a separate one harder. I suppose one could use an L bracket or something.
Might not be the best answer to your question but:
Diy ?
I made a 19" case last week with 1mm aluminum. 1mm sounds like it's thin but it's the same as a hammond tube amp case, it's pretty strong.
Just cut out the alu with a sharp knife, than lightly cut a few times to make the folding edges.
An off-the-shelf case would have been cheaper in hourly rates, but it's custom built and it looks really ok! (i think)