Like titles, lightsabres or armors. Would appricaite!

The items, or information about the items?

In what follows, I'm going to proceed on the basis that you mean "The Dread Masters", rather than the general concept of "dread".

Much of it comes from the missions that are set on / about Oricon, although the sequence begins in the <Story Arc> missions on Belsavis, and continues with various Operations set between Belsavis and Oricon.

Some gear related to that series of missions is available (if you have enough Oricon reputation) from the <Reputation Vendor> in the Imperial or Republic base camps. (Specifically: Dread Guard armour, Hallowed Gothic armour except helmet, some other oddments, including a schematic for Black/Deep Red dye.) Other gear and titles arrive for participating in missions related to the stories, and the reputation you need for the vendors comes from completing missions.

Other stuff comes from completing the Dread Fortress and/or Dread Palace operations.