Custom 5x5 Keypad Design for Raspberry Pi (Calculator Project)

I'm seeking a professional who can assist in designing a 5x5 button keypad for a custom calculator project. The keypad should be compatible with a Raspberry Pi 2W.

Key Requirements:
- Tactile Functionality: The top priority of this project is to ensure that the keypad has a satisfying tactile feedback. I'm open to your expert recommendations on the best approach for this, whether it's using mechanical switches, membrane pads, or another method.
- 3D Printing Ready: The final design should be ready for 3D printing, and delivered in an STL file format.
- Button Size & Layout: The buttons should be similar in size and spacing to those in the provided image, arranged in a 5x5 grid.

Additional Support:
- Material Suggestions: I would appreciate recommendations on suitable materials for both the buttons and the frame.
- Electrical and Mechanical Guidance: Since I lack experience in keypad design, your guidance on how to make this work electrically and mechanically will be highly valued.

Ideal Skills:
- Proficiency in CAD modeling
- Experience with 3D printing
- Knowledge in electronics

Please let me know your thoughts, estimated timeframe, and cost for this project.
Thank you!