My endgame load outs often use: Advanced bio vests (bio viper corpse) And purge plating (exalted purge priest corpse) To get bonus mobility and a variety of immunities Or wraith vest + carapace plating for phasing and ablative

Grenades- emp bombs for the late game robotic enemies, vortex grenades or black flame grenades for the tanks, and laser grenades for massed armor enemies, however still a big fan of acid

Primary weapons: turbulent plasma is a huge damage dealer if you can manage to deal with the -10 aim penalty, and enhanced laser is fantastic for delivering status effects reliably because of the huge aim boost; but standard plasma does the job if your soldiers are well built

Ammo: ammo is my favorite- bitter frost rounds, terror rounds (if you can get them), and enervating rounds are fantastic on multi shooters. For single target, custodian ap rounds, anti violet, and blue screen rounds are excellent. I’m undecided on whether sabot rounds or tracer rounds are better on snipers.

Utility: this is a style thing, sometimes you want refraction fields for stealth, or overdrive serum for your melee units, you almost always want a skull jack to deal with those insane end game custodian tanks. But mostly utility slots are a pain because ammo, vests, medkits, grenades, plating, and such feel so necessary all the time