I agree with qorax. Goods to carry and goods to follow both use the same form B4 . B4(a) is just the extension of B4 means if you don't have enough space left on B4.
Take two B4 forms one for goods to carry and one for goods to follow. You can write on top of each B4 with hand "goods to carry" and "goods to follow" just to distinguish from each other
Describe the category of items on each B4 and its total value in CAD and then details on seperate sheets and attach sheets to each B4. You also have to sum up all categories on each B4 and write total value. If you want I can email you my lists of B4. Good luck