Corso Riggs Customization 5
The Corso Riggs Customization 5 is a Taris Companion Customization Vendor (Republic) item which can be found in Star Wars: The Old Republic.
To get this companion customization, simply go to the planetary Companion Customization Vendor and purchase it.
Corso Riggs Customization 5:
Original Corso Riggs:
How to get the Corso Riggs Customization 5
The Corso Riggs Customization 5 is a customization you can purchase directly from a vendor in-game, you don't need to purchase it from another player and there's no secret way to get it. All you need to do is go to the vendor and buy it, and most companion customizations only cost between ten thousand and twenty thousand credits.
The Taris Companion Customization Vendor on Republic side is located in the bottom floor of the Cantina near where you load in. The vendor is a blue Nautolan called Tatrog standing in the very back of the cantina. The quickest way to get there is to use the Taris heroics quick travel (otherwise just fly there on your ship), and there is a quicktravel point called Olaris Mess Hall in the cantina. You'll likely be able to find this customization at all the other Republic customization vendors as well.
This customization can also be purchased on the Imperial side from a vendor called Denvas Ran, Companion Customization Importer located in the Cartel Bazaar section of the fleet (southern elevator, there's a quicktravel point there). The vendor is inside a shipping crate.
Corso Riggs Customization 5 zoomed out:
Original Corso Riggs zoomed out: