I've got a pair of 240 radiators, currently using low speed yate loons. While this is fantastic, on the cooler days it is overkill so I'm looking for a controller that I can customise to turn off the fans when the sensor is reporting under a temperature, and then scale them up using a curve that I specify, even if this is just 3 or 4 points (like @ 35°C fan = 25%, 40°=50% etc). Failing that, I have a NZXT Sentry LXE but it doesn't appear to work with the yate loons (no fan speed sensor cable) should I just grab some gentle typhoons and try to work out the Sentry?
Look for the alphacool heatmaster. Its available with watercooling uk and aquatuning as well. Its the cheapest option to do what you want, while even controlling your pumps. I am running the software for it on win7 64 bit without any issues.