Your gear is more than ready, but only you can say if you feel ready.
Honestly, I'd say that if it's something you're really worried about, run some non-heroics first to make sure you're holding down threat correctly. Once you've got those down, H AN is probably the easiest to tank. It sounds like you've done your homework and have a lot of knowledge already, so I have a hard time believing you're going to be "that fail tank." If you're really concerned about it, try to find someone who is a tank playing on an alt and ask him for pointers as you run. Most people love to mentor others, and it gives you a sense that you're being supported while you learn.