The prices I find are so high that I hope I am looking at the wrong products!!
Your 9 MHz of 12 bit data is about 108 megabits per second, and apparently that puts you into the top of the line of the National Instruments DIO device families.
There is a much much less expensive line of NI devices, but they are described as being software timed, with one sample per I/O request. There is no practical way to get 9 MHz of I/O requests issued within MATLAB itself.