Durant: +2 Def
- Victory Road
= 40%, compared to Woobat's 10%, Mienfoo's 10%, Deino's 20% and Boldore's 20%
Jellicent: + 2 Special Def
- Routes 4, 17, 18, Driftveil City, P2 Laboratory
Alomomola: + 2 HP
- Routes 4, 17, 18, Driftveil City, P2 Laboratory
Audino: + 2 HP
- pretty much every route (in rustling grass)
These are all BW locations.
List of Pokemon by EV yield
I would go for this set:
Ferrothorn @ Leftovers/ Rocky Helmet
Ability: Iron Barbs
EVs: 252 HP, 88 Def, 168 Sp. Def
- Leech Seed
- Protect
- Spikes
- Gyro Ball
Ingrain isn't a good move for Ferrothorn. It can't switch out as a result, and a Heatran switch in will OHKO you.
That's a more competitive set. Use Power Whip when dealing with Jellicent or Alomomola, otherwise you'll be there all day.