Looking for some easy ways to keep the temps down in my shuttle which don't involve cutting it up

My SB75G2 is the original Rev1 so I'm gonna swap the psu for a silentx and add some heatsinks to the mosfets. I've also just ordered a Pci slot blower.

I was thinking though of adding a small 40mm fan to blow directly over the mosfets under the psu to keep the PWM temps down, not overly concerned re noise tbh. Has anyone tried this ? How did you attach the fan ?

Many Thanks