We need more pirates!

[Suicide Junkie]

In practical terms, though, I doubt the pirates will have more than 400 or 500 kilotons of warship hardware.

A flagship light cruiser, or a couple of frigates for when you need a show of strength.

Any more, and you'll be burning too much money on maintenance to keep up in the game.
Of course, if you do manange to monopolize the spacelanes and take over a significant territory, you might be able to afford more warships to lean on the other pirates with