The biggest hits I get on this recipe are these:
Black-Eyed Peas with Ginger Recipe
Black-Eyed Peas with Ginger Recipe from CDKitchen.com
I love fresh ginger and haven't used preserved ginger. I'll suggest you use an amount of less of fresh, grated ginger. Perhaps 2 tablespoons, or more if you like ginger.
My basis is that 1/4 cup (per the recipes) is = to US 4 tablespoons, and I surmise that preserved ginger is less potent.
I make my own crystallized ginger. I doubt the crystallized ginger would be any kind of substitute. It is nothing like fresh, and not usable IMO except in baking breads, cookies or desserts. (Or munching, which is why I make mine.)
IMO powdered ginger has no application except in baking. (Cookies, cakes, etc. IMO totally useless in savory recipes.)
The recipes look delicious!