Is coffee a 'soft' drink?
Mountain Dew will just degrade your internals. Coke will probably cause something to dissolve and fall away. Pepsi is ok, though I'm partial to Dr. Pepper.
If you can find some Dr. Pepper or Canada Dry in country, you can't go wrong there.
Good luck, and post pics of whatever you end up getting!
"War must be, while we defend our lives against a destroyer who would devour all; but I do not love the bright sword for its sharpness, nor the arrow for its swiftness, nor the warrior for his glory. I love only that which they defend: the city of the Men of Numenor, and I would have her loved for her memory, her ancientry, her beauty, and her present wisdom. Not feared, save as men may fear the dignity of a man, old and wise." - J.R.R. Tolkien