I don't know if there is a recipe for a see invisibility potion, but if there is not, I don't think people should be able to brew potions of invisibility.
Any time something bad happens, it's *chug*. On a server I used to play on a lot, potions of invisibility were easy to find and buy, and any time one of my evil characters wanted to do anything to someone, they would just gurgle a potion of invisibility and bolt, I don't want to see that here.