Sigs and Avatars are part of the
CIT (City Info Tracker).
Using either the in-house application
TNT - Glycerine Edition (TNT = Titan Network Tracker) or
HeroStats will allow you to track badges and other basic character based information.
Via that site you can go into:
http://cit.cohtitan.com/manage/avatars to play with your avatars
or
http://cit.cohtitan.com/manage/signatures to play with your signatures
Among many other useful tracking related tools.
There isn't a big selection of customization, but word is that our CIT developers have some plans in store for that. However the Titan devs are at the mercy of what little free time they do get to accomplish these things, so no time frame is assumed at this point... sorry.
If you have any other questions please don't hesitate to ask. Might as well ask here now that you have your own thread, lol.