Why not get the Seasonic X750? Its like $10 more and would be very well suited for you.
To be fair, the ###HX series Corsair power supplies *ARE* rebranded Seasonics. I personally have the 650HX and am very happy with it! But keep in mind that this is not the case of all Corsair Power supplies... for example the CX### series are NOT Seasonics...
Are for the processor, using NewEgg's prices, the 760 is $208, vs. $170 for the E8400. That's a $38 price difference, or an 18% price difference. You also have to keep in mind the 1156 motherboards tend to be higher in price than 775 ones. For a $100 total difference in price, it may be worth the jump to an i5 vs. a C2D.
Out of curiosity TD, in your opinion which is better.. an i3 or a C2D (assuming similar clock speeds)?