It's one of those questions they probably put off because it's so easy to help yourself. If you go to the Warmoth sales site, and click on the Guitar->Neck Builder selection from the top menu, the first screen you'll see is
this one. That displays all the neck styles they will manufacture. Pick one, and it'll take you to a configuration screen where you can select construction woods, fret sizes, contours, nut types, finish, etc.
I don't see "Thunderbird" listed, but perhaps you'll see something I don't. If there's no joy, there's a phone number there you can call and talk to one of the salespeople. They're not the fundamentally retarded sales people you may be afraid of talking to; they actually know what they're talking about. It won't be a wasted phone call, is what I'm saying. They also won't pressure to do something. If all you have is a question, they'll answer it and you can get on with things.
Also, they sometimes are able to do things that aren't typical selections from the online sales tool. So, if you don't see what you want, it doesn't necessarily mean you can't have it. Call. It's worth it.