Get a 2x4 GB set of Corsair Vengenace LP. Get a 620W Seasonic or 600W Corsair. If you wanted to OC your cpu get a Coolermaster 212 EVO. Even if you don't it will be quieter and cooler than the stock amd cooler. Other than that everything looks ok.
8gb ram fair enough, but why do you think I should switch to Corsair?