I wanted to say that my son is a guzzler too. When we brought him from the hospital (he was FF), he was downing 4 oz bottles! I thought that couldn't POSSIBLY be right, especially since I'd read BW books, and now looking back I think it was because he was such a big sucker he was just sucking as fast as he could and didn't realize he was full.
When we first switched to Level 2 nipples at 3 months, he did a lot of choking at first too for the same reason you're talking about. We use Dr. Brown's bottles, though, so we don't have a collapsing problem. What I did was started him out on a bottle with a Level 2 (faster flow) nipple for about 2-3 oz, then when he started choking, we'd go back to a Level 1 (slow flow) nipple to complete (we couldn't do Level 1 the whole time because it would take too long and he'd get frustrated and wouldn't finish). After about a week, we were able to do a whole bottle with Level 2 nipples alone. We'd still get some choking, but not as much. After 2 weeks, the choking stopped. I think he must have learned to adjust to the flow?
You might try a Dr. Brown's bottle and see how she does, or try alternating the slow and medium nipples so she can get used to the additional flow. She's probably getting frustrated with the slow flow of the newborn nipple, and I know my son wasn't eating as much as he needed because of that. He'd get frustrated and stop 2-3 oz. before he was really done. Once we got adjusted to the new nipples, his daily intake went up quite a bit! I was surprised how much more he wanted to eat.