You need to use a different item for each letter, so usually banners are used.
Liberty Server
Active Character: Canadian Firestorm
Fire/Rad Controller Level 50
I added a complete walk-through of the process here: http://paragonwiki.com/wiki/Base_Editing
Hope it helps!
Can you somehow trick the SG logo items into writing something, by changing your SG emblem? If seems like it rewrites what ever the new logo is, instead of allowing you to say something cool.