How much engineering are you willing/able to do?
I wouldn't bother upgrading the hull unless it's going to be a "proper" combat ship. A lightweight alloy hull is okay once modded for Heavy Duty.
I'd swap the 7D PP for a 7A unit to improve thermal efficiency and provide more power.
I'd also bung in an 8A PDist, simply cos they're not terribly expensive and minimises any bottleneck - and then mod' it for Charge Enhanced to recharge lasers quickly.
I'd also go for either a 5A shield or a 6C bi-weave (depending on whether combat is to be a one-off or a continuous thing), modded for thermal resistance and supported by a PD top & bottom and Resistance Augmented shield boosters.
My own Anaconda's weapons consist of the following:-
1 x C4 fixed M/C, modded G5 Efficient with Corrosive Damage effect.
1 x C3 fixed Beam Laser, modded G5 Efficient with no special effects.
2 x C3 turreted Beam lasers, modded G5 Efficient with no special effects.
2 x C2 turreted Frag Cannons, modded G5 Double shot with Incendiary effect.
2 x C1 turreted M/C, modded G5 Efficient with Thermal Shock effect.
I start blasting with the lasers, switch to laser+M/Cs once shields are stripped and switch to lasers+M/Cs+Frag Cannons if my target gets closer than 1km.
The turreted beams are on the top of the ship to fire on anything that moves above me, the turreted M/Cs are underneath to fire on anything that moves below me and the Frag Cannons punish anything that gets close to me.
TBH, most of those weapons are stuff that I happened to have lying around so it may not be the optimal configuration but it's the sort of thing that I go for by choice anyway.
I don't think I've ever met a combination of NPCs who caused me much trouble.
I think the main problem you're having is that your ship is hobbled by it's small shield.
Your weapons can't kill stuff quickly but your shield means you can't stay in a fight for extended periods either.
If you're determined to maximise cargo capacity you need to upgrade your weapons so combat will be finished before your shield dies.
Alternatively, fit a bigger shield so you can keep the fight going long enough to finish it.
Ideally, fit a bigger shield
and more powerful weapons, for that warm fuzzy feeling of complete domination over stupid NPCs.
