Course selection for probability research

I'm a prospective graduate student interested in probability research. I'm more interested in applied probability theory, with applications to biology and physics. I was wondering what kind of background I would need for this. Due to constraints in my schedule, I only have room for two of the following courses:

Numerical Analysis
Complex Analysis
Functional Analysis
Mathematical Results in Statistical Physics
Mathematical Physics

Which of these courses would be the most important for PhD applications? Should I be focusing more on applied mathematics or statistics? It seems that many probability theorists are found in the former.

Any advice would be greatly appreciated.