Thanks! No, we haven't really thought about doing anything like that. We'll try to get the whole Scooby gang together for a shoot sometime, but it's tough to find a properly colored Great Dane or Rhodesian Ridgeback dog (and a van that we can paint to resemble the Mystery Machine).
It was actually bought locally at some sort of wig shop. My girlfriend and I live in Russia so I doubt it will be helpful (besides, even if I did have an eBay link, I doubt you'd have the wig quick enough to wear it to your con).