I am integrating with a third party order management system and I have to make calls to it throughout the checkout process. The problem is, I don't think there are many events available because of how the onepage checkout is all done in javascript/ajax calls. There are a few like after saving the shipping method, and none of the dynamic events seem to fit either. basically I need to know as soon as the user is getting access to the shipping method tab to pass the billing shipping address over, then after the shipping method, to pass that over. Obviously there is an event for that. I know there are ones for when you submit an order so that should be good.

I guess I only need to know when the billing/shipping address is saved. I was using controller_action_layout_render_before_checkout_onepage_progress but the progress gets called way to late. It just doesn't seem like there are a lot of hooks through the onepage checkout. if anyone can give me some examples of what they have done that would be great!