You are being guided on the right track. I however am thinking that, for me, Zaino and Klasse might be too much hassle. I've been thinking about this kind of thing for a few years [only had a car for ~2 years], and have not gotten the decision made on what to get. In the meantime, I have used other stuff. When I was little, my family's red GMC Jimmy was fading, and I thought I'd play with it some. At that time, I had Nu Finish and some abrasive compound available. I the time, I did the best I could with those, and made some pretty good improvements. After the Nu Finish ran out, we got some Turtle Wax Finish 2001 which is supposed to be very similar to Nu Finish. To this day, I have used that same stuff on cars that I thought needed better protection than the Meguiars Gold Class which I use on my car can provide. That bottle of Finish 2001 getting empty, so I have been thinking about what to get next. On my thoughts are Meguiars #20 Polymer Sealant and Hi-Temp's sealant. The first because it is well known and liked fairly well also. The second because I haven't read reviews of it, and think it is worth a shot, considering it's small pricetag. Both I would suspect last longer than average.
Like I was saying, I think Klasse and Zaino would be too much work for what I want to do, since you have to have a truely clean surface before you apply, otherwise you will have bonding issues. Klasse does have a pre-cleaner in it's system, so that takes care of that. Klasse is the one I'm leaning towards if I don't go with #20 or Hi-Temp sealant because it supposedly doesn't stain trim like a lot of products do.
Take from that what you want, but it is my opinion after a lot of debating with myself that even something like Nu Finish is of great value. If you want ultimate durability and shine, then Klasse and Zaino are there for you, but you will pay [both time and money...but far less than the price of a new paint job..]
Sincerely,
Kevin