Hi,
Yes, you can connect 12x camera ( PrecisionHD Camera 1080p12x) to SX20 codec.
For your information the "cts-sx20-phd4x-k9" is just a part number for ordering the SX20 and that comes with 4x camera bundle so it doesn't mean you cannot connect other camera like the 12x camera.
Just follow the correct cabling of camera as describe on the guide.
