[Suicide Junkie]

GGmod has that.

An empty hull requires no crew, but the bridge requires 5 crew, and the engines require a couple, and the guns require more. Fighter bays need quite a few techies too.

Lifesupport requirements are based on the crew capacity as well (IE: how many crew quarters you install).

The GGmod computers replace 30 crew each (reducing the lifesupport needed indirectly).
And aside from the basic crew quarters, there are gunnery quarters which give a bonus that applies only against weapons (Less crew per kt for general stuff, but the +50% vs weapon requirements is quite useful).