Sounds like a solid build but what I regretted when I've built mine was not immediately going custom water-cooling. My i-2500k was @ 4.5 GHz prime95'd for 24h but my CM hyper 212+ was so noisy I couldn't stand it. I'm sure water cooling would definitely benefit your SLI GPUs cause them shits gon be noisy, boy!
It's very simple to do a waterconfig. youtube videos are more than helpful. just some food for thought. goodluck with your build.