Depth being the distance between the side of the case that has the rear I/O and the side of the case opposite of that.
The location the case needs to be in is only 13 inches deep, but the width and height don't matter as much. The only requirements other than depth are that it must look decent enough to be out in plain view, it must be $75 USD or less shipped, it must have at least a headphone jack, and a 5.25" or a Slimline optical bay.
I've spent the last hour and a half looking for one, but I can't find any for whatever reason.
alright, so its a little over 13 inches and a little more than 75 shipped, but i personally think its a good looking case and thats the BitFenix Prodigy M. midnight black of course.
i can vouch for this case. i personally own it. and its aesthetically pleasing. and airflow is awesome. can fit absurd length gpus and has a very small footprint.
i tried to be honest. they actually didn't fit. well the GPU Fan bracket fit i removed the 2 80mm Noctua Fans. but the CPU Bracket that just didn't fit at all with that massive nocuta heatsink.