I've just built myself a "custom-designed" computer/monitor stand for my new studio. I'm not much of a handy man ("Andy by name, not by nature", some might say), but I'm pretty happy with the result.
Built from some home-made shelves I pulled apart almost a year ago, it stands a little over a metre high, bringing the monitor up to a comfortable height for viewing whilst standing and painting. I also made the keyboard tray retractable so it all tucks neatly away when not in use.
It still needs a paint job.
I might add castors one day if I feel the need and find the confidence. And when I do that, I might consider adding some shelves to make better use of the space.