Yep, normal spray cans will do. If you want to get fancy, you can use metallic paints from auto parts stores, but most spray paints at any department store will be fine.
If you can, sandblast the old paint off before repainting. Not too many have that option though. A good sanding and wire brush is usually good enough.
I suggest that you stay away from gloss paints. All you really need is a satin-type finish. Other than that, just remember to spray a two or three light coats with sufficient drying time in between. Don't try it to put just one heavy layer on.
Most importantly... make sure the grille patterns match when you reinstall them.
I speak from experience.