Most Tarantulas do not have medically significant venom, they are generally rather harmless.

Both Avicularia and Brachypelma are an excellent genus to start with. They have mild venom, and generally docile (except certain Avics can be flighty). Avicularia make for a more interesting display, if you ask me.

I'd do research and put together a bit of information about them, whichever species strikes your fancy. Once you reassure your father they are not dangerous, he'll come around to them.

Also, assure him that you would keep them in an escape proof enclosure.

They are called Urticating hairs, New World Tarantulas are especially kick happy with them.