I took the super stock Ilya Muromets build I was running and slapped it into my Black Widow. I cut the AMS for the time being and upgraded the engine for more get-up. Though, I may switch back if I feel I want the light LRM defense back. I also tweaked with my ammo due to previous experiences with how my weapons fired, and which weapons I used at various ranges depending on my encounters. One could easily move the MLas to the arms if you prefer to use them to track targets. This would be helpful in those maps with varying heights, allowing you to hit targets your torso can't quite reach. As for modules: Consumable: You won't ever need a Cool Shot, so feel free to run UAV and a Strike of your choice. Mech: I am currently using Advanced Zoom, but Seismic Sensor, Radar Deprivation or Target Info Gathering would likely be better choices. Weapon: I would think AC10 Cooldown would be ideal to get a better sync between your ballistic fire rates. AC10 Range could also help keep your ballistic damage more in sync at range. One could also consider the same ideals for the Mlas, though they aren't your primary weapon system. Keep in mind, this 'mech has general weapon quirks such as: +10% Ballistic Velocity +10% Ballistic Cooldown +10% Laser Range -10% Energy Heat Generation Use this information to determine your Weapon Modules.
If you find you don't use arms as shields much, then this version may treat you better. Drop the arm armor and engine dhs to fit an xl325. Anything you can't fight you should be able to run away from.