Comment shameless plug: www.plexus.com (Score 5, Informative) 262
I work at Plexus, a global Electronic Manufacturing Services company, in the engineering services division. We do hardware, PCB layout, software, mechanical, test, project management, etc. Whatever piece or pieces you are looking for, we can do. If you want to use us for manufacturing eventually, great. You pay for the development, so you own the IP and can take it wherever you want. We work with multi-billion dollar companies but also have worked with 1-man startups before.