It's the PSU.

I had the exact same issue with the same mobo, stripped everything down and went through my usual diagnostics and had it randomly working and then not working with various parts configs. Changed over the PSU (same brand/model) and has worked flawlessly ever since.

My thread about the build should be around here somewhere.

I would say though that I personally would change the RAM over for tri-channel when using an X58 mobo/cpu just because the i7 X58 cpu's are designed for triple channel memory and the added pathways it allows.