How much more difficult is it to find the round type? I have a couple of the other one (one without the front door and another with the door and linkage). I have good heater cores for both, but I wouldn't mind one of the round ones although I hear replacement cores for them are $$$ and a half! The recirc doors/linkage on the one I've got isn't in the best shape and is tougher to install and the round one looks sort of... simpler.
