Ambipom's awesome. :O
Ambipom@ Life Orb
EVs:4 HP, 252 Atk, 252 Spe
In regards to the Pokemon you asked if were viable Dragonite, Salamence, Umbreon and Ninetales are really common. Flareon suffers from 'flareon syndrome' which basically means its got great stats (base 130 attack) - but no moves to abuse those stats. Seriously its best STAB attack is fire fang ._.
With Raichu I'd probably run it like this:
Raichu @ Life Orb
EVs: 4 HP, 252 SpA, 252 Spe
Houndoom is also a decent Pokemon especially in UU
Houndoom @ Life Orb
Ability: Flash Fire
EVs: 252 Atk, 4 SpA, 252 Spe
Eh Altaria, I've only used it once and it doesn't work that well. I run it as a bulky attacker with Dragon Dance, Roost, Earthquake, Dragon Claw and Leftovers.
~Hope I helped and GL in finding a Pokemon for your team!