If you're going to be playing games with it too, unless they will be casual / Flash-based titles only, I'd recommend more than two cores. Although most games can still run on a dual-core, a few are beginning to appear that don't (at least not without applying a hack of some sort).
I'd probably choose an i3 over an 860K or 750K. It will use less power, which means cooler operation, which means less fan noise.