Note that the H50 is neither quiet, nor a great thermal performer...You might be better off with a good tower air cooler (like the Mugen-2) or a
real water-cooling system.
The fan is half the story... Seen it at a friend's and the noise was really disturbing... but I guess it was the pump, not the fan...
See the review in
http://www.silentpcreview.com/article1042-page1.html
Recordings in page 7 with the stock fan at various speeds confirm my suspicion regarding the pump noise, which isn't even covered by the turbulence of the fan at 12V...
Yeah, Noctuas are great... but pricey...
You can see a comparison chart of several coolers in page 6 of the linked review.
IMO, the Mugen-2 Rev.B, hits the sweetspot in terms of price/performance.
I use it on my Antec Sonata Designer (which is a bit thinner than your 590... 8.1" vs. 8.27"), so I don't think you'll have any problem fitting it in your case.
Good Luck !
Lnx2Mac