I'd suggest you carry a fixed blade and a multi tool like the others suggested.
Maybe a Gerber Profile fixed blade. It is equipped to do most tasks, is easy to sharpen, the grip is fairly made for wet conditions and if you lose it you can always replace it when you get back (costs roughly $20). The sheath may suck but you don't use the sheath for slicing and chores right?
As for the multi tool, a Swiss Army Knife would be useful. I'd personally carry a Leatherman Wave.
I would also like to quote one of my posts here because I think it seems applicable.
"Back in the Philippines when I was in the province we used what we call "bolo", "tabak" or "sundang" (all are similar to each other) to do everday chores from cooking, chopping wood, bush whacking, harvesting, opening coconuts and even for defensive purposes. The blade did well and we would replace them only when there is little blade for sharpening. There are a couple of manufacturers that produce bolo-type blades like Kershaw, Cold Steel, Gerber and SOG Fusion series. Outdoor, I'd prefer a bolo-type blade over any survival knife because like the machete, it is a versatile tool. "
You can buy pretty good bolo-type blades for less than $15. They cost less but perform big. Way big than you could ever imagine. Blades can be used for so many things. Try searching for the brilliance of the "Aetas" when it comes to mountain survival and their use of knives and blades (Aetas are one of the minority natives of the Philippines). You'd be surprised.

It doesn't matter if you have a big or small knife with you. It's how you plan to use it.

Here's a sample link :
http://tomahawksurvival.com/2009/09...-guides-tata-kasoy-and-miguel/comment-page-1/
Cheers mate! I do hope you find a knife that suits your needs. Tell us about your trip. Would love to hear about it.