Word of advice - pace yourself. Those are some ass-kicken beers. I think they even recommend drinking the 120 out of a cognac glass, to get the full sensory infusion.
The bartenders won't get give you the 90 in anything larger than a cognac glass, so maybe the 120 comes in a shot glass.
For those of you who prefer a normal pint, Dogfish serves a "75-minute IPA," which consists of the 60- and 90-minute versions mixed.