Whats your budget? The build seems a little unbalanced... a 550 ti is great for say,a $400 build. But i think we could fit better in there.
Try switch that cpu out for a 6300, plenty for games. the toshiba 1tb drive is only $65 at the momment. Get the Antec Neo Eco 620 for $30... 600 watts is overkill but right now its cheaper than the lower wattage, lower quality psu's s its a great deal!! its also made by SeaSonic so you are getting top quality.