SITKA Gear Duck Oven Jacket

If im between a xl and xxl in a under armour hoody sweatshirt what size would you recommend?.

So im 5'3" and was wondering which size would fit best either the small or medium?

can it be used for deer hunting?

If wearing a delta wading jacket over the duck oven, do i need to go one size up on the wading jacket? my size lg duck oven fits nice and snug