1333mhz vs 1600mhz amd rig

Hi guys

I'm currently in the process of building my new rig. The cpu will either be a 955/965 BE or 1055t/1090T BE. There will be overclocking involved. The two ram I've chosen to buy are:

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Now is it worth it to get 1600mhz to overclock better? I've read though that AMD likes 1333mhz better with a tighter cas latency timing. Also should I stick with getting 8gbs or 4gbs? If 4gbs I might get the mushkin silverline edition as they're $30 after rebate and have the same specs as the 1333mhz. My rig will be for gaming and will be the specs as follow

CPU - One of the listed above
RAM - DDR3 4gb/8gb
Videocard - 2x GTX 460 1GB SLI
2GB F4 samsung spinpoint HDD
850w oczgamexstream