My EV's are from the analysis, but I'd like to mention a bulky Arcanine I've been using well.

Arcanine (F) @ Leftovers
Ability: Intimidate
EVs: 240 HP/28 Atk/168 Def/72 Spd
Adamant nature (+Atk, -SAtk)
- Flare Blitz
- Extremespeed
- Roar
- Morning Sun
Intimidate helps it switchin on numerous physical threats. Morning Sun is one of the greatest assets to making Arcanine bulkier. Roar is for unexpected phazing and works well since Arcanine can force switches.
I'm currently testing Draco Meteor + Power Swap Altaria. With its decent bulk and access to Roost, it seems like a good Power Swap candidate. Not only does it let Altaria fire off one of the best moves every other turn, checked only by Registeel, Chansey, and Steelix, it also allows it to semi-check special switchins, albeit ice beam is still your worst nightmare.