Nice build. Can't really say much other than getting an aftermarket cooler since it seems like your overclocking. Overclocking with the stock cooler will get you close to nowhere.
As for the case, Zalman cases are really nice. There's the Zalman Z5 plus for $40, Zalman Z11 plus for $60 and the Zalman ZM-Z9 U3 for $50. They have nice cable management.
i would try to gather abit more and go for a corsir carbine builder series like a 200r-300r-400r i just brought the 500r and im incredibly happy with it exellent cable managment and looks classy andd strong enough to run a truck over it ..if your into that type of thing