CD's catalog adverties that paint as high temperature, and guarantees it not ot burn off. It would be interesting to see what happens....
I used paint from hirschauto.com, which is rated to 600 degrees and supposed to be accurate colors.
As for brushing, Hirsch also recommends it, and it works fine on blocks. Not sheet metal.
Pretty much all the vendors work as middlemen, I am sure your brake lines came straight from Inline Tube. But you probably got a better price than if you had ordered direct from Inline Tube. At least that was what I found when I checked on my order.