Yeah, about 48s up should be okay. This will be pretty matched up with the Elite Fours Pokemon.
Make sure you're prepared with potions, and Revives, and status healers! Good luck! ~
every e4 member has a team of level 48s and one level 50 so i reccomend training to level 55
plus they all have related types. ghost dark psychic fighting i reccomend going against the dark type first