If you already have an airbrush you might as well learn how to use it
There is a learning curve involved that we have all had to go through/are still going through but you only get through it by actually using the brush
However you might want to use your airbrush for everything else but the body this time and paint the shell with a spray can since you already feel comfortable with that.
If you do decide to airbrush the body (I'd give it a go IMHO) then I'd avoid both the Tamiya acrylics and enamels and recommend you go either with decanting Tamiya TS paints (see tutorial section), ZERO paints form Hiroboy.com (EXCELLENT auto base colors with factory colors. They need a clear coat which I personally lay down from a spray can) or try Gunze C series paints - great colors that dry quick and hard with a good gloss.
HTH