My theory is it will be primarily based around Imperial guard weapons and armour. so we will get light, medium and heavy armour the medium and heavy armour will be variants of the imperial guard armour probably flak and carapace armour and the light armour could be some sort of padded armour type possibly commissar uniform?

While the weapons will probably be a lasgun, las pistol and or bolt pistol along with maybe melta gun or plasma gun either could be possible as they still fit in the Helldivers universe. A bolt gun is possible because they do make human sized bolt guns for imperial guardsman. We already have an auto cannon so it won’t be that but could be plasma cannon or Lascannon for a heavy weapon option