Ok, looks like I'll be the first to give a direct answer to your question:
How much would it cost? Thousands. Note the use of plural. Any custom guitar is gonna be expensive, and one as bizzarre as this may well cost upwards of ten thousand dollars.
Where could you get one? Well, I don't know of any big guitar company that would do anything like this, which means you'd have to contact a luthier (guitar maker) in person. (please allow me to take this opportunity to pimp my cousin's business: he makes very good, completely custom-built guitars. He doesn't have a website, but you can e-mail him at rebickguitars at earthlink dot net. Honestly, though, I'm not sure if even he'd do something like this.)
Now the answer to the question you SHOULD be asking: is this a good idea?
No. First of all, this design would be a huge pain in the ass to build, to play, and to store. Honestly, such a guitar would have almost no use beyond decorative, "wow that looks cool" effect. It would weigh a ton and make your shoulders and back sore very quickly. It would be rediculously off-balance on the strap, so you'd pretty much need a third hand to hold it in place while you play it. And it would most likely sound like shit, no matter how well it's built.
In short: if you have more money than you know what to do with and want this guitar solely for the purpose of looking cool, you might try contacting my cousin (rebickguitars at earthlink dot net), or searching for other luthiers to build you one. Don't expect any luthiers to take you seriously unless you're offering exorbitant sums of money.
In shorter: forget it. This idea of yours, creative though it may be, is never going to happen.