You might could find a pair of used receivers that had the spaces, but who knows if it would really end up being cheaper than selling your marker and buying a brand new one. Still, it's something you could look into if you wanted. Might save some money, might not. Depends on what you could find receivers for or what you could sell your marker for.

To have an image in your sig you need to surround the url to the image in IMG tags. I wouldn't personally put a plain image of a 98 as my sig though... everyone has seen a 98 before and a signature is really supposed to be something more unique and/or personal. You could always make a request for someone to create a sig image for you, but I don't know if anyone that does that still lurks this forum or not.