Well, here is an "old style" and simple design that has been retrieved from the past and brought before you.
The Magog has served in many wars and can be easily maintained and assembled in the field. The Immortals maintain many of these as planetary defence units although they can also be launched from Fleet Carriers too. They are small, light, pack a punch and relatively cheep. There are many options for weapon payloads, this one is armed for Fighter and Light Shipping engagements but they may be used on ground targets and in many other rolls as required.
Two Snub Nosed Ion Storm Cannon (Anti Shipping)
Three Laser Lances
Two Concussion Missile Tubes