These modules will increase your velocity and/or agility, or affect your warp drive.
Passive module which increases agility while increasing signature radius.
Passive module which increases agility and velocity while decreasing hull hit points.
Passive module which increases velocity while decreasing cargo space.
Passive module which increases warp speed. No more than three of these modules can be fitted to one ship.
Passive module which increases warp core strength, making it more difficult to warp disrupt, while decreasing targeting range and scan resolution.
Injectors increase only velocity and reduce your ability to carry ammo, inertial stabilizers will increase your signature radius (and consequently your incurred damage) for a bit of agility. Nanofiber structures on the other hand, will provide both velocity and agility (very comparable to each individually) at the expense of structure. And honestly if you've reached a point where your structure is being hit, it doesn't matter how much you have.