Hi Boss
I am a bit out of touch with AMD rigs/setups, but I am sure that the default speed of the Memory will be 1333MHz or 1066MHz, unless you plan to overclock the system use some cheep sticks, as he will not know the difference at stock speeds.
The Motherboard you will be using is rated at 1800MHz for the memory but this will be pushing this AMD setup out hard, I would recommend using some stick that will run 1600MHz CAS 6 if you can, but as said if he is looking for a stock clocked system then just use something like these
http://www.ebuyer.com/product/128491.
I have if you are interested an AMD setup that I was meant to use for a show, but it never came off, so did not get used.
The system is Asus Crosshair III Formula, AMD PHENOM II X4 965 CPU, can also sort you out some 1066 Memory if you wish or faster speeds if required.
If you are interested just pop me a PM.
I know tend to use Intel systems, which are a bit faster than AMD of which i have quite a few bits that i will be selling.
But both of these setups may be a little high end for your needs
if you need any help with setup or spec just shout.