Not quite sure the Dominions would need any special weapons, as their distruptors, torpedoes, even transporters have a tendency to bypass shields ("The Jem'Hadar", "The Search, II") and armor ("One Little Ship", "The Search, II"), and their largest ships carry a lot of those. So maybe just dial up the effects of pulse phasers and polaron torpedoes, plus chance to ignore armor?
The Breen, on the other hand, would probably get those energy dampening weapons ("The Changing Face of Evil"). So maybe like the tacyon pulse, but reduces power output for a time?