Today, I noticed that the requested 5 costumes appeared in our inventory. These were costumes in compensation for switching the static costumes to the current system of costumes for characters created before version 2.4. As I had one of each type, I requested 5 costumes. It's so nice for the company to do this.
Metallic Suit for the fighter. I know of no way to currently get this costume from within the game.
Some red costume for the musketeer. I've seen a few characters with this rare costume so it must be available somehow. The other option I was considering was a blue version which could be achieved by wearing an elite striform armor.
Rescue Suit for the scout. The same look as be achieved by wearing the Rescue Suit armor, which is actually quite common. There were no other interesting Scout costumes to choose from as I already have her green skimpy one as a veteran costume and the orange one as an armor.
I've seen a few low level characters with this costume but do not know how to obtain it. There were many other interesting costumes for the elementalist that were unavailable in-game but I thought their appearance were too similar to the other existing costumes.
Another rare costume that I've seen only only 1 other family.