how to choose a graphics card brand if I'll be doing custom water cooling?

[BooshMan]

So I'm in the process of building my second rig to replace my current one. I want to do a custom water cooling loop on the whole set up which has me caught up on which graphics card to buy. I want a gtx 970 but not sure if I should buy a more expensive one with upgraded performance and overclockin or the reference design. Given I'll be putting a water block on the gpu anyways the upgraded cooling on some of the more pricier cards won't matter but some also have upgraded components and controllers.

 

[Ibreakthings]

Why do you need a custom water loop sounds too complicated it would be better just to get a NZXT Phantom and do some intense air cooling plus with the phantom you can put a 120mm fan INSIDE the case