You can now preorder the Canon EOS 5D Mark IV body with Canon log preinstalled at B&H Photo. The pricing of the body is $3599, whereas the EOS 5D Mark IV is $3299 via B&H Photo and refurbished versions are $2799 via the Canon Store. To add Canon Log to the Canon EOS 5D Mark IV will be about $100 USD.
However, if you need Canon Log equipped EOS 5D Mark IV ASAP, this is probably the quickest way to get one.