Lian Li PC-Q18 Mini-ITX Black Chassis

One of the few small mini-ITX cases that can comfortably support graphics cards taller than two slots!

The build quality is surprisingly sturdy, with most of the case being made from aluminium. The side-panels are screwless, and can pop on and off securely. Almost everything can be removed, allowing for many possible build configurations. The only part that's riveted, and cannot be conventionally removed, is the 5.25" optical drive bay, but at least this makes for a convenient space for stowing excess power cables.

The description lists that your PSU's fan can face either inward, or against the side panel. When I attempted this, the PSU could barely breathe, so depending on your PSU's shape, there's a good chance it may not get adequate airflow when the fan is up against the side panel. Airflow overall in the rest of the case is stellar.
If you use a stock CPU cooler, and your PSU's fan faces into the case, this created a vacuum effect in my own build, where both fans were blowing in opposite directions. Luckily, this was fixed by turning the fan on top of the case around, to blow air in instead of out.

In short, this is an excellent case, and should serve your components well in a conveniently portable form. Recommended!