Probably oversized, but plenty of others around here get away with having ridiculously long sigs due to numerous quotes and links, so I think it's fine. I like the buttons linking to my topics anyways =P
EDIT again:
Think either of these images are better? I cant say I'm particularly fond of the corsair gb in the sig right now... but I gotta put something on that side of the image or it looks empty =/
I wish I could make a little animated overlay of the marine in that first one, but I cant =(
While I fail to understand how space pirates find it reasonable to wear stuff designed ostensibly for the sea and open air (much less carry small-time melee weapons, that's what you have marines for), nice work.
And use transparency, not everyone uses the default background theme.