my mobo is the asus a8n sli premium and planning to choose this ramhttp://www.newegg.com/Product/Product.asp?Item=N82E16820145575
is the arctic cooling freezer 64 pro a good hsf for the optys or should i just go with the thermalright??
Yes, that RAM would be ideal for the job.
When the same fan are used the SI-120 will perform slighly better than AC Freezer64 Pro.
Unless you can find the Freezer cheaper than SI-120, the SI-120 is still the way to go for top perofrmance value HSF.
I can find the freezer for less than half the price of the SI-120. Also, you still have to buy a fan with the 120, s Actic Cooling is much cheaper for me.