At random, I looked at an EVGA (http://www.evga.com/Products/Product.aspx?pn=02G-P4-3657-KR) 650 ti boost.
It wants a minimum 450w PSU. So you are ok.
Regarding bottlenecks: Depending on the application (game?) one component will always have more capacity than an other. If you get a bigger CPU then it will be the GPU that bottlenecks, then if you get a bigger GPU then the CPU will be the choke point. It is an endless circle and is highly dependent on the software running at the time.
Stop worrying about it: Make a plan and stick to it. Today you are going to get the most GPU your budget can afford. Next year after you save up some more money, you can get a bigger CPU.
Not to mention that the bottleneck in your i3 3.3GHz is about a half a mile wide.