CAD Jewellery design for 3D Printing

We are looking for 5 to 10 Indian finger ring designs for men. We will be providing the base designs where some modifications would be required. Output needs to be in .stl format which should be usable in a 3d printing machine. We would also need rendered images of the same. Please submit your bids along with samples of your work. One of the sample finger ring design is attached, remaining would be needed in similar style/theme.