In early campaign or in Career Mode, Commandos are plentiful fodder to salvage. Mod the 1B model into a more survivable skirmisher. Hit-and-run tactics and high Evasion through Sure Footing + Bulwark helps this mech stay alive best (it's still only a 480 Armor Rating, so be careful). **Adjustment: Put SRM Ammo on RT or RL and use LA to shield when needed. Drop some back armor to make that an SRM6, but focus on your facing. Pros: More survivable than stock, almost 100 Alpha, SRM ammo for 25 rounds. Cons: Still a Commando (not likely to survive 25 rounds), no JJ. This build shown using standard equipment. Using + or ++ is unrealistic and not recommended on a mech this lightly armored. I like this forum for reference, and thought I'd round out the lesser-represented mechs, especially since Career Mode brings them back into play.
A bit more practical: 2ML and an SRM6 allows for more consecutive turns of constant fire at very nearly the same damage. This configuration gives you a shield arm and torso as well. Same suggestions apply as above, with the addition of the LA shield. Adjustments: Cutting leg and back armor more can give you one SL, but this mech loses limbs quickly if you go lighter. When I start a new Career, I remind myself of the value of the bitty mechs.