LOL, I remember seeing someone with the Exeter / Constitution in an STF many months ago. I actually gave the guy a salute for having the balls to do that.
That said, there's some different options.
Traditional: 1 phaser array and 1 torpedo fore and aft. This is balanced firepower while giving the torpedo option when the opportunity presents itself. If you want traditional Fed appearance, use phasers, or the retrofitted ones just to make people go "WTF."
All beam weapons: 4 total beam arrays, no torps. Use Beam Overload for the heavy punch, and if you can broadsides. If you for some reason have these expensive weapons loaded, Anti-Proton for the Crit Severity bonus. Any extra damage is a nice boost, especially on a crit. Before you try for this weapon type, be aware that, last I checked, are only available via the dil store and cost a pretty penny.
Wide-Arc Quantums: If you have the Regent class C-Store ship, you could toss in the wide-arc Quantum Torp launcher and opt for Torpedo Spread or HYT. Mount it to the front, and have 3 beam arrays. You can broadside with the beam arrays, but due to the wide arc of this unique quantum tube, you can still fire these torps to the side while broadsiding.