Pokémon White sixth team member

Started a play trough of Pokémon white. I have 5 badges and going for the sixth. I'm not sure which Pokemon to get as a final team member. I don't think an electric type is absolutely necessary so I was looking for something else.If you have any recommendations it would be great. My team: Servine Lv.33 Palpitoad Lv.32 Archeops Lv.37 Duosion Lv.32 Scraggy Lv.34