You get a quest if you go back to eos after moving the story on a bit to Aya. Go to the settlement. The quest giver is near the landing site in the settlement, the ! points to a terminal in my game in the middle of town which i think is a bug, it's the guy standing to the right of it.
That quest tasks you with making pathfinder armor. The materials are likely already in your inventory by that point but are all on eos. This armor has 4 slots.
Buy some augments from the buy sell terminal on the tempest.