Personally, I think the Mars will be most like the Ruger cannon-thingy from the Templars. Slow moving shots that deal energy damage, but with gauss-cannon-like up/down properties and sounds. As for the ship, maybe you could look to the Driver class from Citadel. 10 base combat speed, but maneuvering jets to perk up its speed/maneuverability. Or maybe it is moderately fast but has a burst turning jets to allow it to aim?