In my original description, I gave some creative leeway, but some degree of consistancy must be maintained... most importantly for the Th'Nor class which is used in missions 4, 5, and 6. However, if no-one has claimed missions 4 or 6, or have yet to declare a name, then you should feel free to name it whatever you want... as long as it sounds Narn, and has not been used by anything else. Also, once that name is established, the creators of missions 4 and 6 will need to follow this.
In the interests of depening the player's connection to the characters, it might also be a good idea for characters and wing names to be reused. For example, the Narn wing that jumps in during Primus' C5M2 could play a role in C5M5. It would use the same wing name, and be the same pilots.
As for a location, not a lot of systems have been mentioned on the show, however there is a fan map (well done in my opinion) that has several systems that could be of use to you. It shows one certain Narn system that is close to Drazi space called T'Llin. Since this mission takes place close to Drazi space, it should do nicely... not that the map is in anyway cannon.