It looks like you have a standard ATX mainboard. If it is not enough, look for a better case.

The thing with the psu pulling in air from behind, wasn't that a misunderstood question about maybe only wanting one fan in the case, and somebody thought "oh, it needs to draw in fresh air" or something. I remember flipping more than one psu fan back in the early 2000s ...

I had a system that was overheating and didn't know why. Close examination showed that the CPU HSF was mounted the wrong way such that the CPU fan and rear case fan neutralized each other. (They were facing each other, each blowing in a different direction, resulting in low airflow through both.)

I mounted the CPU HSF in the correct orientation and system temperature immediately dropped.