That is a very good looking build. I would get a cheaper motherboard, such as the Asrock Z68 Extreme 3 Gen 3 unless you want tri SLI. The thermal paste that comes with your heatsink should be good. I did the same as you and bought a hyper 212+, but I didn't think the paste that comes with it would be good enough so I bought some arctic silver 5. Turns out its all just as good really. Otherwise, a very good build, very similar to my own.