The Parang I have seen on most jungle shows of Ray's, is a common design from the Vietnam, Thailand, Burma region. It was likely bought in Thailand when Ray was on one of his many world journeys. It is not anything extra special, just an off the shelf sort of machete. I agree with his choice though, no much sense in spending a lot of money on a machete as long as it can be sharpened and will hold up to whacking the brush!
Another thing to consider, in many countries, particularly underdeveloped countries, it is common to have a local ask for a gift of some item of their choosing, such as a knife or another piece of attractive kit. It may be undesireable to carry an expensive knife ot machete into some parts, you may end up giving it away as a token of goodwill. Nothing wrong with goodwill, just what you can afford! Anyway I ramble on...