Beautiful kittens!

As for the biting, thats completely normal. They do it for several reasnos, one being teething, but mostly its for attention or food. My Trixie had quite the bite when she was that size! You just have to be consistent on not allowing them to bite your hands and they figure it out. Luckily, you have two kittens, because they teach each other that bites hurt (in other words, they figure out biting hurts faster)