I am planning an African safari and would like to hear from you what would be the best lenses to take with my E-PL2. I have today the 14-42mm and the 40-150mm Zuiko lenses, but I guess that I will need something longer. In addition the lenses I have are not very fast and many photos in a safari are taken either at very early morning or late afternoon. From what I saw the Olympus longer lenses are very slow. Are there other alternatives?