if you keep your eyes open, you should be able to find a sale of NH-D14 at that price range...
and yah, the D14 would be better then anything listed or suggested so far. it's "legendary" in air cooling for a reason
otherwise, if you want to save some $. i'm currently using a lucifer V2 on my 6600k and seems to be doing ok. however it may be slightly too tall for your case? (by maybe 1 or 2 mm) i can be wrong about the height thing tho... never owned an azza case before so cant be sure how generous they are on HSF clearances.