So basically I'm about to order Asus M5A78L-M LX V2 motherboard with Corsair 2 x 4GB DDR3 1333MHz RAM, and an AMD FX-4130. I already have a GTX 550TI. I'd like to make sure that they all support each other, I'm pretty sure they do, but the store suggested 1600MHz ram with the motherboard and it seems to need overclocking for that so that made me confused.
If you can find 1333 significantly cheaper than 1600, by all means go for it.
I imagine the store recommended 1600 because in most cases there's virtually no price difference between 1333 and 1600, so there would be no reason to buy 1333.