Crafting the Hunter Outfit will require :
White Jaguar Skin :
When you do the "TEMPLAR HUNT" at "Cayman Sound"(327,334), you will be hunting, and the final Animal is the white Jaguar. After Killing him a Cutscene will start, But after the Cutscene the jaguar is still there to be skinned.
*Can also be Bought at a store.
Red Howler Monkey Skin :
If you are going to look for this RARE Red monkey, Here is a tip from "MagnumZero" :
There is actually a specific island that has a marker for Red Howler Monkeys.
It's "Isla Providencia" (502,44). It's not available to search until about 75% through the main story line. You will end up here eventually though with Vane.
A little more Specific Solution from : z 4assed monkey
Great solution for those who want to hunt in order to craft the Hunter outfit, instead of buying the parts, which is both lame and expensive. To be more specific than "75% through," you first encounter the Red Howler Monkey during Sequence 8's third and final mission, "Marooned." But you can't hunt him during this mission because you have no projectile weapons.
After finishing this mission and earning the Adrift achievement for completing Sequence 8, you can return to Isla Providencia with your full arsenal to hunt that monkey and get the achievement Ted Nugent-style.
*You can also buy it at a Store for 5000R.