According to Newegg's specs, your case is 3.9" tall and that card is 4.72" wide, so on paper I'd say it's a no-go.
I don't think that anyone can assert that Nvidia is better for Dolphin. Currently AMD has some cards out that perform very well with Dolphin. There used to be some Nvidia specific hacks to improve performance that have been removed. I will say in general that Nvidia writes better quality drivers, has fewer bugs, and addresses bugs in their releases. In my opinion Nvidia makes a superior product, but I've owned both brands of GPUs in the past.
I don't think that anyone can assert that Nvidia is better for Dolphin. Currently AMD has some cards out that perform very well with Dolphin. There used to be some Nvidia specific hacks to improve performance that have been removed. I will say in general that Nvidia writes better quality drivers, has fewer bugs, and addresses bugs in their releases. In my opinion Nvidia makes a superior product, but I've owned both brands of GPUs in the past.