My kit just came in a few minutes ago, put this up on the FJ forum
Wiring Guru's - Stock Heated Seat Switch - Page 9 - Toyota FJ Cruiser Forum
Pictures and my thoughts on it.
I actually emailed them asking about compatibility and this was their response:
"Good day! Thanks for your message.
As to this issue, the item can be directly wired into the vehicle.In addition, the item is not Prado specificas long as the vehicle can drill the hole.Hope it can help you.Thank you!"
For those of you still wanting to do this I've found this on Amazon:
Amazon.com: 2pcs High Quality Heated Pad Kit 2 Seat(4 Pads)Heater for TOYOTA PRADO: Automotive
$74 and it looks like it just wires in as a "universal" setup using the 4Runner switches. Not sure if that is true or not but...