Whatever you choose, as a second camera, I highly recommend a Yashica T-4 filled with color slide film to compliment either the Rollei or Leica filled with black and white. The Zeiss glass seems to lend itself to color and the T-4 is pretty good for travel being water resistant and all. It's the only camera I had with me during a 6 week trip through South America and I can't complain about the shots of Machu Picchu I got.
Only problem is sometimes you can't tell where it's focused and you might loose a shot or two to this. An Olympus Stylus Epic might be a good substitute as the Yashica's got scarce and expensive for awhile after they stopped making them.
Hope that helps.