Aren't there some Derelict freighters that one can scan for extra Quantums? (It has been a long time since I played so I don't really remember)
When battling against the Kessok, it was easier if you destroyed their Sensors (at least i think the light ships had very vulnerable Sensor systems)
Also: Fly yourself, don't let the AI do it, that way more of your Torpedoes hit, and maybe you can evade some Kessok Torps, that would have hit you otherwise.