Here's my suggestions:
Salamence @ Choice Band
- Rock Slide/Dragon Claw
- Earthquake
- Aerial Ace
- Brick Break
Salamence has a higher Atk. stat than Sp.Atk., so a physical set will do very good. Dragon Claw runs off the Sp.Atk. stat in Emerald, so it may not be entirely suitable, although since it does get STAB it is still viable. See what you think.
Milotic @ Leftovers
- Surf
- Ice Beam
- Recover
- Mirror Coat
Milotic's Sp.Atk stat is actually pretty good, so it doesn't really need Toxic to do extra damage for it. Recover, however, is evil and definitely worth a slot on any Milotic moveset.
Latias @ Salac Berry/Soul Dew(if you have it)
- Thunderbolt/Dragon Claw
- Ice Beam/Psychic
- Calm Mind
- Recover
Latias isn't really the sweeper of the family (Latios is) but its Sp.Atk. and Speed are still high enough to pull it off. As for the moveset, you can either run Thunderbolt/Ice Beam for type coverage but lose STAB, run Psychic and Dragon Claw for double STAB and then get screwed over by Steel-types (it's not actually as bad as it sounds but...), or run Thunderbolt and most likely Psychic to get a bit of both. Basically, Calm Mind up until you can't take any more hits (hopefully Salac will activate if you use it, increasing your speed) then Recover back all the damage if you feel you need to and start killing stuff.
Vaporeon @ Shell Bell/Chesto Berry
- Surf
- Ice Beam
- Haze
- Rest
Vaporeon looks pretty spare with Milotic in your team, so I figured I'd give him a move that lets him stand out a bit from Milotic - Haze. Basically, if your opponent is the sort to power up with a move like Calm Mind or Swords Dance before attacking, or worse, spam Double Team/Minimize all day (God forbid...) then punish them by removing all their stat increases with one Haze. Rest for lack of a better heal move, and Surf and Ice Beam for attacks since they run off Vaporeon's pretty good Sp.Atk. stat, whilst Shadow Ball runs off Vaporeon's awful Atk. stat.
That's my take, see what you think.