Well, I must say that I`m not to sure if you are really remodifying an existing product, or simply making a copy of something that exist outside of your own country? Either of the two, the idea is very good, and I hope you can make it happen. Just think about the zipper bag, and if that company might see a new market when you start, and enter full scale afterwards...
Have you considered contacting the company behind the zipper bags to perhaps start working directly with them as a distributor? Or do you prefer doing your own bags?
I`ll be happy to help, let me know when you have something to show (business plan or maybe some market studies), and I`ll let you know what I think.
My personal blog on strategy, marketing, branding and general topics on business TheBusinessUpdater.com