Wanpo

I had something similar happen to me when I purchased an EVGA GTX 970 SSC edition. A manufacturer claimed to have made a water block that would fit but realized later on that the pcb designer was different. You could totally skip the GPU until you get a card that will likely be supported such as a reference design. It's always a good idea to wait a bit for block manufacturers to announce which cards they will support and will definitely fit. You could even get a video card which already has a water block on it. What card do you have exactly? I just googled MSI GTX 970 Version 1.3. I came up with the EK-FC970 GTX TFX. (Only compatible with PCB revision 1.3)