Don't let AGE's character design turn you away from the series (Contrary to popular opinion, Flit's not the youngest protagonist to appear in a Gundam show). While the story does contain some elements geared toward a younger crowd, it's by no means a "kiddie" show. The story gets pretty mature towards the end of the first generation, and that first arc's ending is far from a happy one. I've only seen the first arc, so I can't speak for the 2nd and 3rd generations.
As for paints, I don't use one single brand across the board. For spray paints, I use Tamiya Color. You just have to be conservative with them, because you don't get much paint for the money you spend on it. The quality, however, is top-notch. For airbrushing, I'd recommend using either Tamiya or Testors acrylics. For hand-brushing I tend to use Citadel/Games Workshop's acrylic figure paints. Basically, just avoid using enamel paints. Acrylics typically dry faster, and don't chip off as easily.