A smaller DSLR should definitely be something to look at.
Look at the Pentax DSLR lineup, you can get a used one in extremely good shape, and it will likely have full weather sealing - which could definitely be important where you're going, and in the future.
If not that, than go with something like a used Canon 40D (or even a 30D), and a few sweet lenses for it (like a 28 f2.8, a 50mm f1.8, and maybe something super telephoto for wildlife stuff)
Or go with something like a Nikon D80, or D200, a 35 f1.8 and a long tele lens.
Lots of good options.
Have a nice day, Bluename.