The Indigo® Molecular Symmetry Model Set, 62350, can build NH3 to show an example of the C3v point group. Chloroform, or trichloromethane, also exhibits C3v symmetry.
You can also build the H2O2 C2 point proup chemical structure with the 62053 university organic stereochemistry molecular model set & the 62009 college molecular model kit for organic chemistry.