Wow - you obviously have the experience if you are painting that many cars a year (must be a high volume collision shop?) so you know what works.

As a painting newb, I could not afford to experiment so I went by the book (the advice I obtained was from reading and from the show car painters where I work). My second paint job was on my '67 SS Camaro, and I used all of the PPG products with the color coat in the base/clear DBU system. It turned out really nice!