I had good experience with Kingston HyperX 1333 -1600 MHz. modules. If you are not OCing shit out of it, any RAM even without coolers would do just as good job as any most expensive "performance" RAM. Save some money and buy most allowable RAM instead of looking for fast one. Even fastest RAM in the world would ad less than 1% of total performance on systems like that if there's not enough of free memory.