Himalayan Imports has a good selection of bolos and khukris in various finish qualities, all fairly decent carbon steel blades semi-hand made.
Spring steel is pretty good stock for making knives, especially heavy utility knives. In "The Hunted" with Tommy Lee Jones and Benecio Del Toro, they are given instruction on making knives precisely that way. Crude, but should work (along with Tommy's stone knife, of course).
Personally, I like my Desert Battle Rat from Swamp Rat for jungle type work. Maybe not quite as heavy as the bolo, but it is high quality and has other good uses. Any of the bigger knives from Busse will suit me fine. If it had to be just one blade only, then likely a Busse Battle Mistress. For general purpose hand-wielded blade instruments, there is nothing better than Busse processed Infi alloy, nothing. Of course, you gotta be willing to spend $400+, but you get what you pay for.
On the other hand, I'd be sorely put upon to have to give up my Leatherman. If it came down to it, I might leave the Busse at home and take my Wave instead. Hey, it works just fine on dressing elk, moose, lodgepoles, 10p nails, etc. Sure it won't lop through heavy jungle all too well, but then again that's not a place I am as likely to find myself. In a combat environment, I'd definitely want the leatherman more than any other knife.
That big Crain knife that Billy had in the movie "Predator" would be cool, but I hear they are way-overpriced, and Crain doesn't have the greatest customer service reputation.
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)