I am not that familiar with the lenses designed specifically for the NEX line. For backpacking, I try to keep the weight down, so generally just take my 18-200mm. It gets me about 80% of what I want without at weight penalty. You mentioned macro and I have recently acquired a 100mm f2.8 macro. It has been a lot of fun.

Do realize with an adapter, you can take A-mount lenses and use them on the NEX E-Mount. It will make the camera bigger, but you can probably find the A-mounts cheaper. And you don't then just have to look at Sony lenses as Minolta lenses are also A-mount. My macro and a 70-210mm f4 are both Minolta lenses that are at least a dozen years old when I acquired them. Some Tamron and Sigma lenses have pretty good reputations as well. You can find out pretty quickly that the camera body is the lesser cost compared to lenses, but the lenses will hold their value and technology much better than the bodies.