I agree with SynthesisLabs. Create a prototype with a reputable company that are held down to an NDA first.
The main advantage here (from my experience anyway) is that a good patent attorney will upon seeing your prototype, sit down with you and have a meeting for 4-5 hours and think about how the product could be changed ever so slightly by a competitor to bypass the patent you wanting to file for.
You then leave the meeting with a list of patents for many variations to your product so as to close the angles of change that possible competitors could do.
Hope that helps.
Mark
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