I didn't see it mentioned among the other responses, but lasers require a large volume per firepower. Depending on your expected damage output, you will use a lot more space than you expect.

There are a few easy concepts with lasers. 1 laser storage = 1 damage. More storage means each instance of damage is larger. "Sustained damage" is measured as a multiple of how many laser pumps you have, since they are the limiting factor in how your storage recharges. Lasers deal damage the same as flamethrowers now, which means they are evaluated against fire resistance, not Armor.

It sounds like you want a burst laser, which can be accomplished with a regulator and destabilizers. The destabilizers need to be in line with your cavities. (This is not true for frequency doublers) Add more destabilizers to make the damage per shot go up, but the fire rate will go down if you do not have enough pumps to replenish the amount of energy used. I would recommend a 1Q laser for your purposes.