Hi again!
So I opened up the case and it looks like theoretically the MSI would fit, but it would be a tight one, and some wires might brush against the casing. So I bought the EVGA GeForce GTX 980 Ti Superclocked+ ACX 2.0+ instead. It's exactly the same size as my old GTX 690. It should be arriving tomorrow, I can't wait xD
Anyway, I just wanted to post that in case someone had the same sort of question.