PPG certified painter here too. If you want savings yes Shopline is good for BC/CC but by all means do not use the single stage especially if going black. It will die out in no time. As far as clear I have used both the 2002 clears from PPG as well as Glamour and Euro Classic from Transtar. The shopline clears for a daily driver I feel to don't hold up like they should. If you go with shopline base I suggest not going with it mixed 1 to 1 but instead do 1 paint to half a part reducer. no need to reducer it 1 to 1 as it is thin to begin with.