CAD Design with Light Curve and Knobs

I need a CAD design of a square with a light curve bend. The design should come in four different sizes: small, medium, and large. The bottom should be covered with circular knobs, approximately 4-6mm high. The design should simulate plastic material and include snap-fit connection points or joints at the edges or corners.

Ideal Skills and Experience:
- Proficiency in CAD software
- Experience with plastic simulation
- Knowledge of designing for snap-fit connections
- Attention to detail and ability to create precise dimensions

Please provide samples of similar work.