Good news and bad news using catylized urethanes. First the good:
You can use your Paasche, and use a compressor, or an air tank or CO2 tank. It works fine over Tamiya lacquer (I've not used Testors lacquer), Duplicolor, Cobra Colors, PPG, ect. I've used it over decals with good results as well. Because it is catylized, it cure pretty quick, dries rock hard, and doesn't turn yellow. If you have it mixed and reduced correctly, you spray out a very nice, smooth finish right from the airbrush.
The bad news: DO NOT spray this in your house unless you have some serious ventilation to get the fumes outdoors. I advise that you absolutely use a respirator that is rated for materials with VOC, and leave the sprayed body out in the garage untill it cures. It's a good idea to use proper protection for any paint, but the catylized paints are more harmful to your lungs when inhaled.
Overall it's good stuff, and pretty easy to use. Just be sure to be safe, follow the mix ratios and directions provided by the manufacturer, and do a couple practice pieces to get the feel of the material. Regular box-store lacquer thinner will clean the airbrush, so save the PPG reducer for spraying. Good luck, and be sure to post your results!
Brian