Juan,
I have used Dupli-color white primer with no problems. It does not have a lot of filler and I use it mostly as a color stabilizer prior to applying color. Regarding the blue lacquer, I get my paint from the local O'Reilly's and they will order any color I want from their color selection. They have a delivery truck once a week and are happy to include my request in their order. I'm not sure about the same service in your country, but you might want to ask. I also buy their lacquer in the large cans and mix my own color for the spray gun. But trying to match the mix for a repair is impossible.
I've also used their enamel. It works well, similar to Rustoleum, but it's heavier than their lacquer. I only use it for trim colors but the quality is very good.
Paul