I am not sure would need anything more than a utility patent or something to prove you had the idea first - talk to a patent attorney. But patents aren`t always enforcable anyway.
I suggest you assess what ability you will have to defend your idea. Even if you get a patent, you have to have the ability to find those who infringe and force them to stop. This can cost a lot in legal fees.
If you can't defend your patent, then it really provides very little protection. Entrepreneurs and small business owners often find the cost of protecting the intellectual property is more than they have in assets.
I agree with Wisepreneur the patent is only as good as your ability to enforce it. You can do a search yourself on the patent office website. Also, do a web search for similar items before spending any money.
You also have to decide are you looking to license your idea to a company or manufacture it yourself? You can approach a company with a NDA. Do not send them your working model unless they ask for it. Companies don't want to be responsible for items they did not request if it gets lost or damaged.
Boy oh boy there are some smart folks on this board!! Sargent is right in that you absolutely need to do a patent search; first and foremost regardless of your intentions to get one, simply to insure you are not infringing on someone else’s IP. From there, there are 2 main schools of thought… To patent or not to patent…. Some folks are of the opinion “The first one to market wins”. While I do agree that if you can protect your idea, you probably should (or at least get a provisional to explore the possibility that your invention has legs) having a patent is not a necessity or a prerequisite by any means to make a living with your product. It’s all about market share baby! HOWEVER, as Roger said, a lot also depends on whether you want to simply license it or build a company around it. What are your thoughts for this “product”? Do you want to build a company or do you want to take the money and run?