Mine's in an InWin 301. Not the smallest possible, but reasonably compact. No optical drive bay, one 3.5", three 2.5". Airflow is suboptimal, the front fans turn 90 degrees and blow out through small gaps in the side, so I've used fans there with high static pressure rather than high flow rate and it seems to work well enough.
But I'm not doing any overclocking and my GPU is solidly midrange, for a hotter computer you might want better ventilation.
Only small nuisance is I can't open it up while it's in the desk mount, so I have to unplug all the cables and remove it. Don't do that often enough to complain about it, might be able to fix it by dremelign off a chunk of the mount if I were concerned.
Glass panel is not really by bag, but under the desk I don't care about it. Solid side option is available but I wouldn't pay extra for it.
Size-wise, it is very similar to mine, a cheap Itek Patriot Mini, which seems just a bit smaller than yours. 3.5" bays take space.
I don't care a lot about space either since it's under my desk. But I think it would be easy to create a smaller uatx case by dropping fans/3.5" bays/other things that a miniitx drops.
But I'm not doing any overclocking and my GPU is solidly midrange, for a hotter computer you might want better ventilation.
https://www.in-win.com/en/gaming-chassis/301/
Only small nuisance is I can't open it up while it's in the desk mount, so I have to unplug all the cables and remove it. Don't do that often enough to complain about it, might be able to fix it by dremelign off a chunk of the mount if I were concerned.
Glass panel is not really by bag, but under the desk I don't care about it. Solid side option is available but I wouldn't pay extra for it.