It's far from fancy but there's a place in Chinatown that serves twin lobsters, either with ginger and garlic or with black bean sauce, and I think they're extraordinarily delicious. It's on the corner of Elizabeth and Bayard and is called The New Big Wang. The dish is about $20.
Francisco Centro Vasco is a great place for lobster, and very reasonably priced (although the sides -- fried potatoes, rice, salad -- are mediocre). The place has a very festive atmosphere; I bet your staff would have a terrific time.
If you want to go for your basic lobster on steroids, the 3-5 pound kind, then Palm or Old Homestead would work well. They are the size of turkeys. It is quantity over quality but it should impress the rook.