Can say the HAF932 is pretty good, but you'll have quite a job keeping it dust free. Sound is also an issue there because it's as open as cases get. It can fit a 360mm in the roof without any mods though.
Haven't got any experience with cosmos s or LiLi's, but I think TTL can help you with that
3.88 wasn't exactly my most stable, and my 24/7 is 3.2gHz because it's quite a hot bugger.
You cannot use the PCI slots directly below the graphics card. Nearly every modern graphics card has a dual slot cooler, basically only the 4850 and below have single slot stock coolers.
My i7 is cooled by a noctua U12P SE1366 cooler and the two noctua fans it came with. Strill want to replace that with a 360mm WC loop though.