I think you should go with what the pattern says. Buy a zipper and take the whole she-bang to a cleaners or a place that does alterations and ask them to put in the zipper. My sewing machine only made ugly buttonholes. I took a little GD dress and had someone make the buttonholes at an alteration place. It took her less than 2 hours and cost me very little. My dress was a hit! I have a new machine now. If I was close to you I would put in the zipper. Then you are sure everything its and is sturdy and plays well!