Elpida Hyper or D9KPT (second needs some serious volts).. maybe BBSE or D9GTR/GTS. Max around 1600 cause if I´m correct, AM3 can´t do more? Basicly, you can buy some OCZ CL7 and live happily ever after..

My D9KPT can do CL6 1500MHz.. its not miracle, but it can.. and for 99 EUR.. which aint bad..