I'm trying to decide what kind of lens I should bring to Tibet. Currently, I have a 10-22, 18-55 and 55-250. For this upcoming trip, do you think I should bring along 10-22 and 55-250 or 18-55 and 55-250? Alternatively, should I sell my 18-55 and 55-250, and get a 18-200 instead?