www.LEDGroupBuy.com is now carrying heatsinks for DIY LED reef lighting. There is a wide selection of extruded aluminium heatsinks.
In a DIY LED lighting project, one thing that is very important in the build is cooling the LEDs. LEDs can last many years at 12hrs a day (10+) but their life expectancy has strong connection to the temperature they run at. The cooler they run, the longer they will last. You can keep your LEDs cool by using aluminium heatsinks to thermally conduct the heat from the LED star to the heatsink it self. The heatsink can also be cooled itself by providing fans by either blowing air down into the heatsink or sucking hot air away from the heatsink depending on the ambient temperature of the room.
To pickup some heatsinks, you can check them out here
To pickup some fans, check them out here