Okay! Well depending on what your use is for the build I can start recommending the best parts Are you going to be gaming? VIdeo Editing? File Conversion? Web Browsing? Cad?..etc.
I think that all the parts you selected are compatible and will work in that build. The CPU seems to be the bottleneck and the slowest choice. With those 2 480 video cards, why not chose an i-7 980X? It would be a benchmark record breaker. However, if I was building a system, I would only install one video card, probably an HD 5870 and use just 4 GB or RAM with an 1156 chipset.
Answer to your first question: Yes. Everything is compatible.
1] If you are considering water cooling, have a look at the Gigabyte GA X58A UD7.
2] The Corsair Obsidian 800 is a great case specially built for water cooling setups.
3] The Corsair 950TX will be enough to power your overclocked rig.