It's the right spot. And you've done a great job choosing parts.
The dual/tri/quad core debate goes on. The good news is that your choice of MB and CPU gives you a shot at getting a x3, or possibly even an x4 CPU with the MB's core unlocking option. You might, or might not, get an extra core or two running strong and stable. It's the 'luck of the draw'.
The only item missing - and it's optional - is an after market CPU cooler. Since you've chosen the Black Edition CPU I'm guessing you're a bit interest in overclocking. To help you out there a good HSF comes in handy. Sunbeam Core Contact CPU cooler