I have the door hinges which have the hole for a mirror arm. Right now I have a jurry rigged Series III mirror assembly on the drivers side and nothing on the passengers side. I would like to mount mirrors on the hinges like they are supposed to be. I know that the style of mirror head is up to me and I am leaning towards the rectangular ones over the round ones but which mirror arms do I need to buy? I know that the current SIII arm won't work. Thanks in advance.