are you talking about the salawar yataghan, a.k.a. the khyber knife, like this one of mine?: (22in blade, 5.5in grip)
the best thing is they are not thick, they have a reasonably thin blade with a 'T' section spine to provide stiffness & thus are fairly light and maneuverable. mine feels realy good in the hand, i've also got a thicker modern indian copy that feels like a piece of rebar in comparison.
i got this one a few months ago on ebay, it was listed as a 'jungle machete' in an estate sale....
they were used by the hill tribes (pathans) in the khyber pass area of northern india/afghanistan (and now pakistan) also known as the hindu kush.
musta been pretty effective as they made alot of them.....