30 years old with a 3.34 GPA in History w/ a cert in Homeland Sec. Studies AF OTS or Navy OCS?

I am interested in pursuing a career in intelligence in either service but want to know which one I might have the better chace at. My dream is to serve 4-6 years and transition to the CIA, DIA, NSA, or serve my 20 years as an Intel Officer. Also, which of these two services is the better fit in terms of preparing me for a possible career with a government Intel agency?