I don't really know much about anodizing, but if you decide to paint it, I can offer you some help.
You can't just spraypaint metal. If you do, you'll find that it begins to flake off after some time (a week, two... depends on how much contact the material has). This happens because the metal doesn't really bond all that well to the paint molecules. If you want to paint metal, you first need a
primer.
A primer essentially makes the metal a lot more pourous so that the paint molecules bond to it better. However, just like paint, you should sand the metal before applying the primer. Some people say you should sand the primer using fine grit sandpaper and apply a second coat before you apply the paint. You can get primer at home depot or any automotive store (Pep Boys, etc.)
With the paint, you should do atleast two coats, three coats. People recommend you again sand using fine grit sandpaper in between coats. When using spraypaint, the important thing is to do a cross-hatch pattern -- a 'coat' consists of a very light spraying in vertical lines and very light spraying in horizontal lines afterwards. Don't use too much, though - you get terrible results if you add too much paint in one coat. The end product comes out a lot better if you use too little paint on a coat but do several coats than if you add too much paint on one coat.
Finally, to get that shiny automotive-metalic effect, you need to buy clear-coat spray. This is exactly what it sounds like - a clear coating of paint. Its this stuff that adds the shininess to your paint job and makes it look like a car.
The biggest drawback to spraypainting is the time it takes to get a good job. With atleast one coat of primer, two-three coats of paint, and a layer of clear-coat, the whole process can easily go over a day (you need to give a few hours for the paint to dry in between coats).
I learned about all this from case-modding sites (some people are crazy enough to make their computers look like ferraris ;-) ). If you want more details, go to sites like
Virtual-Hideout or
Bit-Tech and search their forums for "painting guide"