Sourcing the commodity COTS parts is not so difficult. Having someone on your team who has buying experience in the mechanical or electronics space certainly helps, because they can leverage their relationships with suppliers to get faster service and better prices. Also, multiple vendors frequently carry items of similar specifications, so you have considerable flexibility in selecting vendors who can work well with you and your business.
This article builds on content developed by the Martin Trust Center for MIT Entrepreneurship for MIT's Orbit Knowledgebase and is licensed under CC BY-NC-SA 4.0.