I've never done this, but if anyone knows what you need, it will be people at lankota and you will also need the help of the people at headsight.
I have put a 600 series header on a 9000 series, and it works great with the help of these people, not sure if they make kits to go back to a 20 series combine.
Do you have DAM already? If not, you may want to consider stepping up to a
9000 series