I'd say four quantums, but an even slower rate of fire. The pulse phasers, and phaser strips should be used primarily as short-to-medium range defensive batteries, vs. small to medium sized vessels with a fast recharge rate, but a lower damage yield.
A crap load of photons from four, forward-firing fixed launchers, and two aft, should round out the ship's offensive capability nicely.
It's not a god ship, but this is a vessel that should be able to take on a NeghVar, a Warbird, or a group of slightly smaller ships, and expect to win. Offensive capabilities should be about equal to a Sovereign-class, particularly from the frontal arc. Her weakest spot would obviously be the aft quadrant.