Your card now i believe only recomends a 300w psu, plus your 95w CPU, you still have a 100w overhead. It recomends a 400w psu or greater for a 650ti. You add in the 95w the CPU would use.. yea I'd recommend a new PSU. 600 to 650w would be good. That would give you some overhead if you want to add another card
Maybe this PSU?
Rosewill Green Series RG630-S12 630Whttp://www.newegg.com/Product/Product.aspx?Item=N82E16817182200
well rated PSU, but i don't know your budget. If budget isn't a problem i recommend a corsair PSU. Cost more, but very well built