Currently, the only way to change the appearance of your fangs & eyes (as a Vampire obviously) is to use /vampirism fang <0-6> and /vampirism eye <0-15>. It's working, but not really an ideal way and players often don't know about new styles. So, maybe a customization GUI would be a great addition and could perhaps be added to the skill GUI. Here's a concept art:

added with b5e9e66

that is a good idea. i will look into it, but i think this is easy straightforward possible.