Would you like a different kind of potion, mechanic-system, item or just something different added to the module? Just write your idea below, I'll run past the DMs if they agree I'll go ahead and try to create it.
Here are a few examples:
"I want a potion of disguise that changes my char look completely!"
"How about an arrow that can turn someone into a chicken?"
"Militia needs a stun gun!"
"Why can't I have a crowbar to force open locks and doors!?"