Sinistra.

I went down to the guitar store "Portland Music Co." on Broadway today. It's smaller than the one on MLK, but deals exclusively in acoustic guitars. They had some pretty nice 12 string guitars there for a cheap price. They were all right handed. But, the guy showing me the place told me that they could probably order a left handed one. I asked which company he would suggest for getting a 12 string from. He suggested Martin, since they probably wouldn't charge extra to make it left-handed. I checked their site, the cheapest one there is $819... so I think I might hold off on trying to get a hold on a twelve string for a bit.
If I ever make it big, I'm going to have a guitar company make a sellable custom guitar thats left-handed.
-Tom