#20 is pretty good, but I like #16 even more. You might also consider using #20 to lightly polish and seal the paint and top with #16. Since you polished out the paint real good, you can probably go with #20 until the next deep polishing is needed.
The Klasse twins are also good but if you want to try using what you have on hand first, I'd go with #20 topped with #16. Barry has a nice stock of #16 on hand at Wash-Solutions....by the way, Barry says "Hi".
Great job on that big rig. Between boats and big trucks, I think you would be lost of someone called you to detail a Miata!