*Oh noes! lookie, I'm a SEED cosplayer!* XD
Anyway...I think someone asked a similar question about another UC uniform...I don't remember what character it was....(I don't keep track of UC), but it had a very similar design on the front. You might try doing a search on this forum to find it and see what people said about that.
Personally I think I'd cut out the shape you need in a gold-colored material and top-stitch it on with invisible thread. You'd probably have to figure out how to turn the edges under a little so you don't have fraying fabric on the top of the uniform.
As for the tassles, I know there's a pattern by one of the major companies that has like a fairy-tale prince costume with similar shoulder pad tassle thingies. I can't remember what one it is, and that particular pattern I don't have on hand, otherwise I'd check for you. But it might be able to give you some ideas.