PhD statistics with MS in CS?
There are plenty of PhD Statistics programs that would want you, just because of your background. Keep in mind that their are tons of PhD Statistics programs in the USA. You can apply to 10 relatively low ranked ones, and and 10 of your choice, and see from there, for example. One thing to reiterate, ranking is just a relative number. If you graduate and are seeking a Data Scientist position, and have a M.S. In Computer Science + A PhD in Stats, your good no matter where you went.