You might want a slightly thicker board if you're using mealmine. Something around 3/4" thick or so, as melamine has a tendency to sag if you have too long a run of it. By run I mean if you have a long length of it with nothing supporting it. If you look at the do-it-yourself portion of the forums you could find some really good plans on how to put a rack together. You might have to customize it to your specs but otherwise there are some great step-by-step plans there.

Good luck!