Clomid & Nolva are quite similar, so I don't think you would benefit much from using both at the same time.
If you're using Human Chorionic Gonadotropin (HCG) at the end of the cycle, use it with Nolvadex since it's a stronger antiestrogen.
If you want to try it, just use 10 mg of Nolva ED with Clomid.