I beat him with level fifty Pokémon, so you aren't too far off. Though, I would do some training. I can actually help you with one of your problems, Ludicolo, seeing as I had the same one.
You need to hit him hard, and fast, this way he can't Doulbeseed you. (Leech Seed to gain recovery, and Double Team to avoid you. Plus, he knows Surf and Giga Drain, so keep fire- and water-types away. Your solution; a dragon-type. Salamence works wonders, as does Shelgon. Though, Altaria is your best bet. Make sure it knows Aerial Ace, and go in swinging. It can't hurt you, both Giga Drain and Surf are ineffective against it. You should have no problem beating him after that. I'm surprised you haven't had troubles with Gyarados.
As for Milotic, you NEED higher levels. It will continue to slaughter your team, if not. What I did, was use my Castform, and Hail. Yes, it boosts Milotic's Ice Beam, but it keeps you resistant to both it's Ice beam AND Surf. My Castform also knows Thunderbolt. Go figure. So I swept the table there too.
Castform is so useful. *pets Castform*
Hope I helped.