I appreciate the info, but i already know that the breathers are already kinda high for the front diff, ADD, trans and transfer case. They are in the same location as my previous FJ Cruiser and Tacoma. Where I live, the places where we wheel, you can find yourself in a hole above the door handles and to the windshield very quickly. I rather be safe than sorry. It's not that big of a deal to relocate the breathers up higher. My plan was to move them to the same location as I did the FJ Cruiser; inside the cab.
As for the polyethylene mufflers, here's the link to the kit I was referring to. I remember ARB using the same polyethylene mufflers along time ago and you could only order it from Australia, but now they have a black circular flat style breather.
Differential Breather Kit - Raw Mind Engineering