I made fitted cloth diapers for my babies back in the dinosaur days. I used safety pins to close them snaps are expensive. I wouldn't put snaps in the inside to hold anything since it is next to the baby's skin and might irritate. I used an insert I could buy at the store in a box like a Kleenex box and laid a sheet inside the diaper. the sheet could be thrown out and saved a lot of "messy" diapers to clean. At that time the disposable were just coming in and my kids were allergic to them. Those have changed a lot. I don't have a pattern anymore for the cloth diapers but I may be able to remake one.
Lynda