Since the description states that they wear minimal clothing (and thus, probably little armor), I'd give them a natural armor bonus of at least +1, maybe +2.
For attacks, I'd go with the obvious 2 claws option (since the sloths I can think of usually have large claws to help them climb), and probably give them a rake attack with their rear claws. Alternatively, you could give them "opposable feet", like some primates have, where they could wield a dagger or other light weapon with their feet for an additional attack (with additional penalties, of course).