I have a 6 month old and wanted to see what type, nylon or neoprene, and/or brand of vests people have liked the best for comfort, safety, and having the kid enjoy wearing.
Get a super thin comp vest so he can wear a shirt over it and look like all the cool babies! Just kidding, make sure you get one with the flotation around the head and a crotch strap so he/she doesn't slide out.