Well, as the owner of the Acacia 8 string Iceman, I can fully recommend Scott as a great guy to work with. And I think he should be able to build you the body shape you'd like. I've never owned a Carvin or Siggery, so I can't give you any kind of direct comparison, however.
Also, as you eluded to, he's located in the US (it's not a matter of xenophobia, it's a matter of paying out the ass for and being unsure of the whole importation process. I totally get that. And, as has been mentioned, Siggery would involve the same process)