Vibrant Viridis breeds blue lines, you should message them. Be prepared to spend something like $2k~$3k for a neo though. If you guys have never owned a GTP before though, I wouldn't start with that investment on a neo...
If you join the green tree python groups on facebook, you'll find breeders and can look through snakes you might like. There's also a GTP forum to post this on, http://moreliaviridis.yuku.com/