Product Prototype

I'm looking for a skilled freelancer to prototype a combination of physical and software product. I have complete specifications and a clear timeline of 1-3 months. You will need to take my detailed concept and refine it, while testing and analyzing its effectiveness as you go. You should have a thorough understanding of design prototyping, and possess the technical skills to execute a project of this nature. Ideally, you will also have relevant experience in software design and development, but I am open to any freelancer with a strong technical background. The resulting product must operate efficiently, fulfill my needs, and be up to standards in order to reach completion.