However, keep the case open and point to the cards a largish table fan and than it could be quite a nice rig ...
The side panel on this one almost is a box fan.

yes it is but that fun is so slow, but not noisy. HAF in reality is not high airflow, but half passable and not noisy airflow
yeah. i have an AZZA Hurrican case like that: tons of very slow airflow. my cards are touching 80 C, which is a bit warm for my taste. i have a couple of fan voltage regulators on the way...