Is the seasonic x 850 good enough for custom water cooling (a future upgrade) and dual SLI 770 4GB?
i would suggest you give us a full list of your build including a link to the water cooling that you are looking at its your best chance to get an accurate answer.
Search tachyon 550. My build is ripple dragon. I'm unsure of water cooling parts as they will be an upgrade. Trying to replace the tachyon 550