If you're going for the SG05 w/ picoPSU, then I'd get a Scythe Samurai ZZ for the CPU cooler.
I've just ordered one for my build (migrating from a P182 to an SG07). Its dimensions are pretty much perfect for any mini-ITX motherboard. In 3/4 directions it basically skirts just around the LGA1155 mounting holes, thus clearing the PCI-e and RAM slots when the CPU socket is squished right up against both. And then you just need to choose which direction the fin mass goes. It can either go parallel to the RAM slots, or towards the back of the case just slightly over the rear I/O ports. If necessary, you can bend the heatpipes slightly to allow the fin mass to clear any obstacles.
I might be wrong on some of these things though, gotta wait for the parts to arrive first. But I'm basing my comments on many hours spent over the past week comparing photos and putting a ruler up to my monitor to judge the dimensions.