Trying it out in new battle mode, because can't wait for it to show up in the main campaign. Turns out that either I did something dumb or the mission fields terror units.
The best armor for doing this kind of missions is Ragnarok. 50 armor all-around, resists, can fly and has decent inventory. Ghost is good too: invisible, 30 armor, and built-in weapons ignore armor, which is handy. And Slave, being the Bio Suit-lite allows for tanking a lot of damage with resists and regen (can gals wear it though?). Thief has brutal penalties, so I'd advice against using it. Others are up to you.
Equipment: you can bring parrots, 2x1 melee weapons (and force blades, for some reason), pistols, smasher\sawn-off, and SMGs. Also any medi-kits, alcohol, 1x1 grenades and other minor stuff.
Given the amount of armor you can face, you should go for highest damage possible, like:
-Handcannon\HE acts like poor's man grenade launcher, with 50 dmg and bad accuracy;
-Eagle\MAG with 50 dmg;
-Magnum\Chem with 44 acid dmg;
-Gauss with impressive 70 dmg!
There's also other pistols, but these ones are relatively abundant.
Also bring small medikits, smoke grenades and explosive grenades just in case. Getting hit is inevitable, and healing is required.