I wanna say it’s called the Legionnaire Armor in the store sometimes?

Yep, SC-37 Legionnaire. That's the one I run, since armor seems to do so little. Might be an argument for medium or heavy armor vs. bots, but I value the mobility and stam regen of light armor too much to switch.

I’ll have to give stun grenades a shot. I typically use the impact grenades on bots since they insta kill walkers and help a ton if you’re getting swarmed by a pack of the chainsaw arms dudes.

I run the Slugger as primary, partly because it helps me survive either of those in a pinch. For chainsaw bot packs of three or less you can give each a stagger in turn to prevent them from closing with you. As long as you start before they're on top of you and don't miss, they'll be dead before they reach you. Versus walkers you can shoot the hip joint to stagger them, and they don't shoot while staggered. Four or five shots destroys the leg. Not a very ammo-efficient way to kill a walker, but a pretty safe method if none of my teammates has an angle on them.

The Slugger also one-shots all chafe bots, is surprisingly accurate at range and can one-shot devastators if you hit 'em in the face. Tough to do at range though as you have to account for bullet drop.

Slugger stagger is also excellent vs. bugs, the stagger can interrupt bug breach call-ins even if the shot doesn't kill the bug. It's been my go-to primary for all situations since the Breaker nerf.