It depends what your budget is, and for what major purpose(s).

Here's really good suggestion based on budget, information. Keep in mind though it's Australian prices (and generally within the country), so chances are it'll be half the price in America.

They're talking about 3rd generation i5's though (you could go for the i5 3470), so if you want to stick with 2nd generation I'd recommend getting a i5 2500 (you won't need the 2500K unless you wanted to overclock). Also, an ATI/AMD GPU is generally very budget efficient in terms of what you get for your money, though I prefer nVidia.

Honestly, most people would barely use 6GB RAM let alone 8GB, though I guess it's cheap enough. Either way you do not need more RAM in that suggestion you've linked.

Hope that helps somewhat.