Good idea flipping the fan around since the noise was from turbulence between the fan blades and the heatsink fins. I'll have to keep that in mind for future fan noise situations. From the photos, it looks like air should still flow through the heatsink in the reversed setup. If not, you could always add some plastic shrouding to help direct the airflow.
Usually, fans are set up to blow into the enclosure to increase the internal air pressure thereby preventing dust from getting sucked in from every little opening in the panel, cover, etc. Thus, an air filter just needs to be installed at the fan inlet. Just something to be aware of, depending on the environment you're going to have your supply running in.
I've been casually looking at high-current supplies for a somewhat esoteric use. In order to fully adjust my electronic load (60V, 60A, 300W), I need a variety of voltage/current combinations from 62V@0.5A and 50V@6.2A to 17V@20A and 5V@75A. This unit almost covers it and at a reasonable cost.
Linear HP supplies that I've used have quite a bit of headroom above the quoted specs. Do you know if that's the case with this SMPS model? If so, how much (e.g., how far above 60V or 50A will it go)?