I'm very successfull with 2x large gimbaled beamlasers efficient g5 on the top side of my Python. Pulses would work also, with emissive munition mod even better.
I target the powerplant and with some trigger discipline i can always shut it down without destroying my target. Most annoying enemies in this scenario are DBX's and everything with rank below expert. They just die too fast.
I've equipped also 1 packhound mount to strip PD's if i can't take down PP (DBX's -.-') so that i can still use hatchbreakers during the target stays mobile.
Do NEVER fire multicannons with corrosive shell mod. Do NEVER use frags, PA's or fixed weapons like railguns. You want to be fast and successfull, also the target should survive! Even the ones that have the skill to take out a PP with fixed weapons...against NPC's for pirating it just takes too much time and cops show up or the target goes high-wake. Railguns are very likely to kill the targets with the last shot due to overkill.
Piercing is the most important stat where you should pay attention. Class 3 thermal weapons are the best choice for that because if they pierce, they damage the module and don't damage the hull. Even if they don't pierce and hit the hull, most NPC's use only up to military grade armor which has higher resist against thermal weapons than kinetic. Missing the module with a lasor is lesser worse than missing with a canon! The chance that they are survive is much higher than with kinetic weapons like the canon.
There is a huge difference in choose of weapons if you wish that your target survives (long enough...) than if you just need a clean kill