It's unlikely that this is real phong shading. Phong shading in such applets is usually faked by a "phong map" used as a spherical environment map. jPCT can do that too, but to combine it with the normal texture, you would have to use blending (only available in software mode) which includes a bumpmap. You could supply a plain bumpmap (all texels 128/128/128 in color) if you don't want to see bumps on the model.
