4 vials/packs with no starter, 2 packs with a gallon starter, or one pack with a gallon starter on a stir plate
...or that's what Mr. Malty likes anyway. That pitching rate calculator is pretty reliable. You really should use a huge amount of yeast for that kind of OG.
Personally, for something that size, I'd pitch onto the cake from a prior batch if I could. Not strictly necessary, but over pitching is hard to do in my experience.