Frazzer: the sig does look great. however, i do think you might as well go all the way and slap a background instead of having that black emptiness there.
deviantart.net has alot of good tutorials teaching you basically anything you want. just search for "nebula tutorials" and you'll get tonnes explaining how to make your own custom nebula. im not saying the entire thing should be colorful, just like a nebula effect around the edges perhaps with a bit of blackness in the center.