Heh. Fell, you are aware that you can modify your first costume without being level 20? You can modify costumes at any time, it just costs influence. As does the new costume. Level 20 just gives you a new slot. So if you ain't going to use that outfit any more, just modify it permanently. And it is very expensive - it was 12k for my level 20 character (i made level 21 today) for each segment - 12k for the cape, another 12k for the top, another for her trousers and then 4k for the head and hair. Expensive.
On the subject of capes, experimentation has revealed the following information. Long hair, a lot of the medium hair, and the first ponytail are all no-nos. They poke through the cape. Now, this might not be an issue for you since you are a flier, and the cape just says close to your back. But SSG is a superjumper, so the cape goes right above her head on her way earthbound. So long hair was poking right through and being very obvious about it. I ended up using a medium length hairstyle that has no pokey down bits to get around this, but UXB might not have to worry, depending on how the cape moves.
Capes are very cool btw - i found that when doing my swipe attack (where SSG does a baseball throwing move, only with claws) that the cape moves around as it should during that.