I think the core 2 duo e7400 is a good pairing with the 260. That motherboard is solid, but it won't let you overclock much if any. Honestly, I don't think there would be a big difference between either system.
Just for the knowledge of those on this forum, I have an e7300 on a P5KPL/1600 Motherboard and it is currently running perfectly stable at 3.2Ghz, as opposed to 2.66Ghz stock. With the help of an Arctic Cooling Freezer 7 Pro Rev. 2 and a slight voltage tweak.
And yes, it will easily beat the AMD, even on the lower clock speed. Hope this helps.