Have these modules:

Heavy Thetacron Cannon x8, Dominion Cannon - Mark III x4, Korteth Twin-Blaster x4, Hypercharged Bane Emitter x2, Overcharged Bane Emitter x2, Ion Pulse Ballistae x4, Psionic Amplifier, Lazuli Mind Controller x3, Exotic Pulser x3, Combat Analyzer, Prototype Mech XV

Attack is over 6,000 unbuffed, looking to get it higher mainly for planet grabbing.

Aside from rankig points into attack - Do I go for missions, or NPC's. And if so, which one. [Not doing Caephlon, just spent 15 levels of ~2200 energy trying to get him and I'm tired of that.]

Okay, At your level I was basicly the same. 2 Things i did were get the Leviathian Rift Emitters, which give a total of 120 Attack, and the Modulated Xecti Disruptor (for me it gave 40 each because of Konqul).
Basicly then point your Rescued Prisoners into Tac. Officers. If you are content on your decks. You will be surprised how quickly it rises.

BTW, if you want to do a long mission, you can do the Taltherian, where the 2nd last mission gives the Taltherian Sentry, +55 Att/+55 Def, x4