I purchased them from RW Carbon, they were reasonably priced at $185 and designed to be OEM replacements that fit into the slots and catches for the original mirrors.
I ordered them November 24 and they were delivered on the 29th (five days with the holiday in there to boot and shipped all the way across the country).
Here they are installed:
Passenger Side
Driver Side
Full Car
The fitment was excellent and they look great. I did have some questions about installation and they were promptly answered by RW Carbon via email. Overall I would recommend them.