XT looks good. I also checked the Heatkiller, there are 3 different versions just for 1156. The most expensive one seems to be just for looks, like a Ferrari or something to car buyer. That leaves the other 2 just $20 apart. It looks like the difference in those 2 are bits of metal and plastics.
My goal is to overclock to 4GHz range but not to the extreme limit, would the $62 heatkiller suffice?
I already have a 655 pump (no speed adjust), a Danger Den 2x120 single pass rad with a pair of 140mm Yates on top of the rad (80 or 90 CFM each), and some reservoir that holds 1/2 liter water with easy fill port and all using 1/2" ID tubes. Since it's mostly low restriction loop with a powerful pump, the CPU block would be the deciding factor. I seems to remember something from long ago about how some blocks don't perform well in high flow loop.