Welcome Brett...:welcome
The Zaino over SG would be repetitive and since the objective of these newer acrylic/polymer products is to develop a molecular bond with your paint. I'm not sure that combination would work.
I have seen some use AIO as a set-up for Zaino.
There is a bit of a running debate on Carnuba toppers for Zaino so I'd get familiar with the search capabilities here. There does seem to be some agreement on toppers for AIO/SG.
My recommendations are, all disclaimers in place -- YMMV, would be:
1. Decide on one system or the other Klasse or Zaino, they are both very good.
2. Do your research here on application techniques as they have much to do with the success or failure of your detailing efforts...believe me I've failed simply because I didn't know how to apply.
3. Preparation is everything...what you do to your paint prior to these systems will make the difference and you’re at the best place around to research the products and techniques to get your finish ready.
4. Ask questions as you're doing your research and post pictures.
Good luck,
Russ