you are better off sticking with air and getting a decent HSF
With water cooling the heat still has to be blown away, so tehre is a fan there, so you may aswell save the money of a full water cooling loop and get air, which will give you just about the same temperatures as water if you don't overclock, and not much worse (provided you get decent HSF) with a decent OC on.
If you have a mid ATX or full tower case, then either Prolimatech Megahalems or thermalright Venemous x are the best air out there now, but are pretty big, which is why a mid or full tower is needed. Both come fanless, but a couple of Noctua fans, which have lots of airflow and are quiet, will do the trick. Scythe make some pretty good fans too, but for quietness you will want a gentle typhoon.
They will work without a fan, however if your airflow in your case isn't very good, your temps will be getting hotter than you would think comfortable