Well, it looks small, fast, and maneuverable, so I picture this as an FAC, or a Fast Attack Craft- or perhaps as a medium corvette at the most. As such, I'd arm it with heavy frontal torpedo, and pulse-phaser batteries, and a number of medium-strength phaser arrays to provide coverage to the other arcs.
She's equipped for attacking large, heavily-defended HVU's, and getting the Hell out of Dodge. This sucker doesn't slug it out- she dances, and strafes, and then performs a few tight evasive maneuvers as she escapes at high-speed, out-running the less-maneuverable survivors, and depending on her very strong aft shields to protect the ship from return fire.
Alternatively, this ship would make a great reconnaissance ship, a high-speed courier/transport, or as a light escort for large, fast Federation cap-ships- such as the Century-class.