Root Beer Recipe

I am going to give root beer brewing a shot. I just ordered a pound each of sarsaparilla, birch bark, cinnamon sticks, spearmint, star anise, and orange peel. I also have vanilla extract, sucrose, local honey, and brown sugar and I'm trying to source some wintergreen leaves. I came up with a recipe using other recipes and trying to imagine them... However, all the recipes I see use volume measurements and it seems like the ingredients should really be weighed. I'm trying to figure out if I need more sarsaparilla to do 4 or 5 batches (five gallons each). This is the first recipe I am planning on brewing... Anyone have an idea of how much a cup of Sarsaparilla weighs, or how much a half cup of birch bark weighs?

1 cup Sarsaparilla
1/2 cup Birch Bark
1/3 cup Wintergreen
1/8 cup spearmint
1/8 cup orange peel
1/8 cup Star Anise
3 sticks of cinnamon
3 Tablespoons of Vanilla Extract
1 cup of local Honey
9 cups of brown sugar