Hmmm... Messed around a bit in photoshop attempting at a new sig. This is what I came up with. I can't decide on wich on to use though, if I'll use them at all. What do you think?
I think the large border suits that banner, it makes the inner graphics stand out more. I would go with that one, Mechanic. ;-)
As for the border, if you're using Photoshop you can use a 'Stroke' in order to create a border. Once you finish your design, merge the layers and go to Layer > Layer Style > Stroke. Then make the stoke appear, 'Inside' the image. Alter the other things to change the border color and size ect.