Where do you buy poison of paralysis in oblivion

All you have do do is have a high alchemy level. if you want to make a potion of
paralysis just get your hands on some spider dadras eggs or whatever that stuff is
they drop and some cleanfer( don't think that's spelled right ) claws. if your a master
you could just get one. im not sure where you can purchase one though. if you want to
get a high alchemy level, just duplicate a bunch of ingredients and make them into
potions.