hi there. I have noticed this forum is a little empty, so I'll go ahead and comment.
I originally really wanted to pursue a global/international health mph, but after extensive research on what kind of opportunities exist in public health, I decided to go with epidemiology as my concentration. a lot of positions really want you to have some computer software and quatitative analysis skills, even in the various other disciplines, so I though epidemiology would allow me to markey myself in any aspect of public health, really. The tangible quantitative and analytical skills will help you in any area of discipline within public health.
In my opinion, epidemiology is probably the most practical and allows for flexibility in what you want kind of research or applied health projects you may want to work on in the future.
hope this was somewhat helpful