Good set up.
Also, I am not quite sure on the CPU Coolers that I'll get. I do not want my case to look messy, and I also want to look for the best value for money.
Currently, one of the favorites is the Hyper 212+. Or you can get the Core Contact Freezer (buy bracket separately), Mega Shadow,etc.
Here are the top heatsinks: http://www.frostytech.com/top5heatsinks.cfm
The only other upgrade I see useful will be an X25-MG2 or other good SSD as a boot drive. If I were you' I'd get the CPU cooler and depending on the need, get the SSD. If SSD is not needed, save the money and get a 2nd 5850 in a 6months-year or so and CrossFire for cheap.
This would be a quite a bit on your part on research,etc and if you'r planning to do a high OC, you may want to look in to REAL water cooling: http://www.tomshardware.com/forum/256607-29-watercooling-read-first
This will cost you ~$250 or so just for the CPU loop. Add the GPU, and cost skyrockets.