L.F.
I too am a belly sleeper. When I had my two daughters body pillows weren't on the market yet. I used a medium firm King size pillow. It worked great! It allowed me to sleep as close to on my belly as was comfortable. The body pillows I have seen may have too much loft to be comfortable for a belly sleeper. Experiment... you may find a soft pillow works now, but later on a fatter pillow will be necessary. Body pillow may work well, too, especially for sleeping completely on one's side.