I can help with basic block textures, but i unfortunately can't make custom mob textures. I am working on a texture pack, so when I'm done with that i can send you a download of it to show my work. We can chat on skype about how you would like the textures to look. I can message you my skype name and username. I can't wait to see this mod out and would love to work on the team.
P.S.: can you recommend a modding class of a type?