I'm thinking of doing a portrait/avatar pack with original art for Sins but rather than replacing the default set, I'd like to add on to them so that players can have more choices to pick from.

(Warning: link whoring!) My portfolio can be seen here: http://theopticnerve.deviantart.com

As it currently is, I'm a bit confused and n00bish with some technical details and would like some information on how to actually get them to be seen in-game. I've found four .tga files that deal with player portraits but the grid layout for them seems a tad bit confusing and vastly differs from each other. There seems to be a lot of space and empty grids open in each .tga for more portraits, but is there a way for the game to use any of these empty grid boxes and if so, why does each tga have such different grid layouts? Lastly, what would I need to do for the game to see these new portraits in the empty grids?

Ex. 1 (in jpg format)

Ex. 2 (in jpg format)

Ex. 3 (in jpg format)

Ex. 4 (in jpg format)

Keep in mind that I'd like to add on to the default player portraits and not entirely replace them.