Stratios can do both exploration and combat PvE (up to an extent) , unfortunately i only used it for PvP , so you may have to ask around for such fit , as for exploration i just use an Astero.
It depends on what sites you want to approach with the Stratios , in terms of pure combat or both exploration and combat sites , also depends on the region you’re doing , wormhole type, etc.
But as a general rule , cloak, prober, mwd, single/dual repairer , hardeners, 1-2 DDAs, zeugma analyzer, cap battery(ies) , maybe a module that helps with scanning , as for the rigs they can be astronautic rigs, cap rigs, scanning rigs,aux armor pump, nanobot repairer, etc.
Maybe this will help you with your Myrm level 3 missions: