If it were I, I'd take my Contax G2 kit (G2 body, G1 body, 21, 28, 45, 90 lenses) and all the film I could carry. So in your shoes, I'd take the Leicas. Sure, there will be some shots you can't get with them - closeups of flowers and insects and the like - but there would be plenty of others you'd miss if you dragged along multiple camera systems and were fussing about which system to use for a given shot. The handiness of rangefinders plus the lack of a mirror letting you hand-hold in low light make them the best travel cameras.