Talk to the Small Business Administration: Www.sba.gov. They can give you advice and help you secure the funds you need at a favorable interest rate. Be careful about taking your product to an established company unless you have patented or copyrighted your product as they will be able to replicate it if it is good.
You should start the business by taking funds from the bank or you should also give a business proposal to an already established company. And in the end you can also start up a partnerhisp with your family or friends. Whichever option seems feasible, go for it.