Yes, I would do a patent search first as many "great products" are already patented. If there is something already there, see if your product is different enough to move forward with. Unfortunately, you can spend a tremendous amount of time and money to produce something only to find later that it is already patented. Would advise you hire a patent attorney to search for you (and you will certainly need one to draft the patent application). Remember, you want to file ASAP and you will be protected from the filing date if the patent is approved, but it takes about 2 years for the approval process - thus all of the above due diligence is important.

Second, find a good CAD designer who you can trust unless you are a mechanical engineer and can draw up the design yourself. If you really have something patentable, you should have a non-disclosure agreement for everyone to sign (CAD designer and prototyping company), these are not rock solid, but make people stop and think.

Third, if all of the above is a go - then find a company that can facilitate manufacturing in the US and/or Mexico in the beginning. Low volumes can still be produced in the US. Larger volumes need to move to Asia/China, but you do run the risk of copying (if you have a cool/unique product). Google "rapid prototyping" and many of those companies can handle cradle-to-grave from design to mfg'ing low quantities for you.

Good luck.