Increase the Power Plant by 10 tons to cover the weapons. Now we are at 78 tons total of added items. Upgrade the Sensors, so there is another 3 tons. 10 tons for a Shallow Penetration Suite. Now we are down 91 tons from our 201-ton cargo bay. So, 110 tons of space remaining. Problem is, this isn't a real merchant ship. It is a Q-Ship. So, Captain, Pilot/Astrogator, Engineer, 4 Gunners, and call it 20 Marines. Means I need 4 staterooms and 20 tons of barracks for a total of 36 tons of Accommodations instead of 80.5 tons, a savings of 44.5 tons. Add that to the 110 tons from cargo space and you have 154.5 tons of "free space". This is more than enough for 20 or 30 more pop-up turrets.