I run the supertalent cl9 2000mhz bought from imicros $109
http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWNX:IT
There is also dual channel 2200mhz by supertalent cl8.
http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT
Imicros is Ewiz out of Cali
Personally i wouldnt even bother with 6 gigs, I run dual channel myself on X58