You are off to a great start, Nathan. You really slammed it & it looks very cool. Very clean building & conversion work.
Since you have an airbrush set up, you can use just about any paint as long as it is properly thinned & compatible with the plastic. I would stay away from bomb (spray) cans, they are expensive compared to a bottle of paint. Plus, you can mix your own custom colors & control the paint flow much better.
There are also pearl powders you can purchase for acrylic & solvent base paints you can mix with your paint for more custom options with the airbrush.
Hope this helps & please keep the project going.