I've painted several freezers, and it's easy to get a pretty good look. I would definitely use an enamel style appliance paint, or at least something designed specifically for metal. sand with a light grit sand paper, clean with damp cloth, dry, prime and paint. Follow the paint/primer application instructions exactly. Lots of light coats, runs happen very easily.
The problem with any spray paint in a can is that you'll never match the quality of your factory painted appliances. They are powder-coated, enameled, or some similar baked on application. spray paint just doesn't have the same longevity. While you might be able to get it too look very similar at first, in a few years there will be stains and nicks in it that wouldn't occur with a factory painted appliance.
I would try a couple different brands of gloss black on a scrap piece of metal to test which best matches your appliances before committing to half a dozen cans if the match is really important to you.