Yes I would have to say its the same size/fitment switch for a 2500 see this vehicle here and scroll down to the interior photos http://1017.ecarlist.com/web/ebay_photos/1382521/
The heated seats run through a module not just from the switch to the seat. These are great questions and we are still trying to determine if just the switches and module is needed. I would imagine there should be a pig tail harness under the seat for the module, Are you able to check for this? If this harness is not present than a body harness would need to be purchased.