I am happy to see you followed some of my advice on your gpu issue, the Asus Gtx 560ti is cooler, silent, and has high quality components, according to the manufacture they will last 2.5 times longer. Not to mention that it has a standard factory overclock, and all this for an extra $10, a great deal.
Now about your power supply, it has 550 watts, which should be more than enough, if in doubt go and check with this psu calculator
I ran a calculation on your pc and it came out to be 472watts so your psu should be enough.http://antec.outervision.com/PSUEngine
Happy to help