never purchased from this place but they have been around for a long time.
http://www.frozencpu.com/cat/l3/g30/c309/s1876/list/p1/Liquid_Cooling-Water_Blocks_VGA_-_Card_-_AMD-HD_7990_Water_Blocks-Page1.html
Was also recommended to use this website by several forum regulars. So i would consider it safe. Its nice to see they have this stuff, i'm probably going to use this website to get the aftermarket fans.
I've purchased at least $500 worth of parts from frozen cpu - Radiators, tubing, fans and custom connection kits.
Definitely a trustworthy company - and their custom products are well made.