Build Advice Planning my future case build!

Hello Bit-Tech!

So, I've been gathering components slowly but steadily, and right now my rig looks something like this:

• Maximus Formula VI
• i5 4670-K
• G.Skill Trident X - 16GB
• ASUS GTX 980 - Reference

Now, it's all currently stuffed in a CM Stacker 935, and I'm planning of fully upgrading it with an extra 915R. I plan to watercool all of the hardware, and mod some of the insides' of the case (there will be a worklog... eventually, since university takes up most of my free time and I do need to save up all the cash and stock the materials!).

However, I'm here right now looking for your advice regarding the next step. I thought on getting another 980 to put them in SLI, however all "Reference Designs" are long gone in Spain, so my question is:

Would I be able to plug in any other 980 (a STRIX, for instance) without sending ripples through Space-Time continuum which would possibly lead to the End Times?

And yes, I plan on squeezing all that power to the limit!

 

They will be fine any 980 will do SLI with another regardless of the make. The only thing to bare in mind is that both cards will run at the speed of the slower, but it won't be hard to over clock them and get them running the same or quicker