If you're using acrylics, then Vallejo also do RLM colours, in both the ready for airbrush Model Air, and the standard range, the latter being more cost effective, as they go virtually twice as far when thinned.
I'm not keen on acrylic paints, but having used a couple of the Vallejo colours, i have to say they work beautifully and, for acrylics, are relatively resistant to abrasion, lifting etc.