Is the oil intended for someone that doesn't want to get "high", or are they OK with being stoned out of their mind? Two different ways to go about it, and you can use any type of flower ..... even ones very high in THC to accomplish either. In my experience, a full spectrum oil using flowers that are high in THC, and some flowers that are high in CBD gives the best results for people that suffer from seizures. If you're interested I can give you more info either here or via PM.
Good luck