I second the Mugen 2, you only need one, but you can add another fan for a little extra cooling, although I think the ultra kaze 3000's are really loud.
All you need is the Mugen 2 really, it comes with a fan and thermal paste, however if you want to get better fans and thermal paste, to get better temps, you are more then welcome to. I can't really say what the best thermal paste is, because I use Tx2, because it came with my cooler. Fans it depends on how much loudness you can tolerate.
Also remember, you don't need that much thermal paste, a rice sized dab in the middle will do fine and then when you apply the heatsink, the weight of the heatsink will spread the compound out, you can wiggle it from side to side as well to aid it in spreading. If you use too much you can actually hurt your temps.
Good luck and make a build log when you get it so we can all follow you!