Usually the ones operated by Qatar Airways and Finnair

Seriously though, if you've never flown long-haul business class or first class, the step up is so major that if you get any of the products, you will be very happy with it.

Since there'll presumably be two of you flying in business class, my take would be to try to fly one way in the yin/yang "old" Club World and one way in the "new" Club World. That way you can say you've tried both of them and can then argue happily on here about which is better. If you're flying First it's all much of a muchness.

Doors on seats have yet to cause peace in the Middle East or cure the common cold, so I'm firmly in the could take it or leave it camp (ie - I don't care at all and would not book a product for a door). If it is your first time though, I'd be aiming to try both types of seats if possible. It'll all depend on, as others have said, finding availability on the dates and route you want. Once you have that, whatever business class is on the plane operating that route is what you'll get.