I'm going to say up front, I'm no expert in this area, this is just my general understanding. From what I understand about financing anything (be it a car or hookers & blow), if you could get financing for something like this, you probably don't need it (you have enough money to just buy it). Getting financing for something that's probably worth or will sell for less than what you have into is hard to impossible. Getting financing for luxury items is harder (i.e. getting financing for an ATV versus a car).
That being said, my understanding is that you can buy whole kits, or you can by these things somewhat piece-meal as you build it. So you can buy this part or bunch of parts, build that portion of the car, buy another set of parts and build that part. Kind of like financing it.
If you have the ability to finance something like this, you may be able to get a built one. But you still run into it being an expensive luxury item. To get financing on the kit I think would be nearly impossible.