Realistic 3D Portrait for stone machining

I need a faithful, realistic 3D likeness of one person for 3D printing. The final piece will be a head-and-shoulders bust, the mesh must be clean, watertight, and manifold. I have a few good photos—and can supply them the moment we start... (Budget: ₹600 - ₹1500 INR, Jobs: 3D Art, 3D Design, 3D Modelling, 3D Printing, Blender)