Take my word for it, Datura and Dramamine aren't worth fucking with. If you are determined not to take my word for it, Dramamine is pretty similar and a lot safer.

Take too much Datura and you're dead. How much is too much? It's very difficult to know, because it varies plant to plant. I'm sure you can die from taking too much Dramamine, but at least you can accurately gauge the dose.

Nothing I ever experienced on these drugs was interesting or enlightening. Some of it was horrifying. Typically I ended up curled up in a ball waiting for the madness to end (which took hours). 0/10 would not try again. Reliable source of bad trips.