Design & Build Prototype for Invention

I'm seeking an expert with mechanical engineering background to bring my concept sketch to life. The project involves a mechanical device that will invole a retractable movement like a wall mounted clothsline. The product is for the sporting market. I need a professional who can help me design a functional prototype from the initial concept sketch.
I require the services of someone in Australia.
Futher details will be provied after a Non Disclosure form is signed

Skills and Experience:
- Mechanical engineering
- CAD software proficiency
- Prototype development
- Prior experience with radio design preferred