Zipper (or other closure) for the quilted vest

I'm making my second School Days Jacket, including the quilted vest (which I'm making with sleeves so I'll call it the quilted jacket). I'd like to make the quilted jacket also be able to sometimes be a standalone lighter jacket for non-rainy days, but I'm trying to wrap my head around the cleanest way to add a zipper or some other type of closure to it. I'm not sure of the best way to accommodate the zipper and the bias tape without it looking obviously tacked on. Any ideas for how best to insert a zipper or other closure options? (I've made the quilted vest without the coat several times and did toggles on one and a belt on the other, which were fine but I'm not sure about either for this application since I think it'll get a bit messy with all of the other jacket closures.) Thanks!