Both specialties are going to be hard to match into. You probably need Step 1 scores above 230 with honors needed in most clerkships your third year. YOu'll need to honor your clerkships within the specialty during the beginning of your fourth year. If you want to match at a program on the coasts, it'll generally be harder than programs in the midwest. Again, this is a broad generalization. Clearly, CCF and Northwestern are going to be competitive midwest programs. Finally, doing a little research into the speciaties is important to at least have something to talk about during your interview in regards to research.
In general when you start interviewing you'll know if you're going to match. If you get about 10 or more interviews, you'll probably end up matching. During the interview process, it's nice to see the same faces where you go. If you see the same people, it means you're part of the herd that will match.
Anyway, these arguments as to which specialty is harder to match into is somewhat inane. Going into a surgical specialty is like going into a marraige. One just knows this is the one and nothing else will do. So, if you're looking to go into a specialty because it's "easier" you'll probably be disappointed and not match at all. During the interview process, it's been fairly easy for me to tell which applicants are the ones with drive and those who got there just based on grades.
