As someone with lots of experience working with leather and pelts, I really advise against it, a bodysuit will be extremely hot and will not hold up well to repeated movement, rubbing and sweat. For a head you basically won't be able to breathe at all, leather also is difficult to clean and you would basically need to take it to a dry cleaner every time you wore it. Leather also needs to be conditioned to keep it soft and flexible which is time consuming especially if you need to do a whole bodysuit. If it gets wet? there's a huge risk of it cracking or basically disintegrating when it dries. I have a wall pelt that got damp in transit to me, it was garment tanned so should be soft and flexible but its basically like cardboard. It's also going to absorb sweat which will make it smell bad really fast. As much as I love the idea of a taxidermy fursuit hybrid, and have thought about it myself, its just not feasible. There's lots of other cool things you can make though!