Hm I was going to suggest one that uses a notebook style PSU as these are totally silent, like the morex or tranquil, but I think they all have only slimline CD/DVD drive bays, which you don't want.
As maybe you know, 5.25" drives use a lot more power than the slimline versions, which means that a notebook style PSU could possibly be inadequate. As a side note, the best thin drive I've heard of is this one, as it is slot loading (no flimsy tray) and DVD/CD+RW: Panasonic
For this reason, all the other mini-itx cases I know of have low profile internal PSUs with noisy 4cm PSU fans, which you would have to mod to make quiet - I don't think there is much to separate them, to be honest. I've heard the Chyang Fun one isn't bad; here's one at linitx.com