Custom Plastic Casings for Velux Blinds

I need two solid plastic casings (left and right) for a Velux window blackout blind kit. These casings, referred to as ‘end caps,’ are placed at the base of the window. Their purpose is to hold the screen and a wire that supports the screen's up/down movement.

Requirements:
- Dimensions: Approximately the size of a 50p UK coin
- Material: To be determined (please suggest the best option)
- Design: Smooth surface finish

Ideal Skills and Experience:
- Proficiency in plastic fabrication
- Experience working with various plastic materials
- Ability to create custom shapes based on provided dimensions
- Attention to detail for a smooth surface finish

Please provide your best material recommendations and any relevant experience in your bids.