From the listed above I would chose 5dIV.
My main wildlife camera is 5dIII, which I chose over my 1dIV and before 1dIII. FPS are great for me if I am doing BIF only, but even 5dIII is good enough (I have few BIF on my web taken with 5dIII).
Mainly I am photographing animals from hides on very short distances, so silent shooter was the reason why I bought 5dIII, not 1dX that time. However, if the FPS are most important for you, 1dX is the answer.