There wasn't really much in the area of automatic avatar resizing mods, most either slowed the persons PC down or slowed the forum down. I could just modify the image resize mod to work with avatars, but it's not too rough to resize an avatar- and if it's resized it will have a smaller file size so it will mean faster downloading on peoples PCs. Well I'll consider adding it later, you can just ask me if you need something that's animated resized.
Edit: Though it seems that you deleted your responding post, as per request here is the version that fits within 120 width that you needed for another forum.