I rarely use gifs, unless dealing with monochrome or boldly coloured pics.
Jpeg at 5-10 ratio work nicely.
You sig is a little over 500 pixels wide, and about 150 tall.
It should fill the gap beside your profile bar nicely, without cluttering threads too much when you post one-liners.
It weighs in at less than 40k, so it should be fairly fast a download once users get it in their browser caches.
...
It feels so weird watching something I pieced together myself.