Hmm I've heard Hawaiian Baby Woodrose/Morning Glory seeds (LSA) are like a mild form of LSD...which itself isn't "just like" shrooms, but it should do as a legal sub. I hear they can give you nausea so be careful if you have a weak stomach. Oh and San Pedro/Peruvian Torch cacti are almost exactly like peyote, but they are sold legally for ornamental purposes. I think a simple alcohol cacti extraction would be your best bet if you don't mind the work.