There are 2 "styles" european headlights for w123. Round ones and square ones. Which one is better for light output? Why are there 2 styles of euro headlights?

For those of you that have cracked your glass or had it pitted, how much was the bosch replacement glass? Can it be ordered from the MB dealer? I know most dealers parts departments are not familar with european equipment for a 20yr old car. Thanks in advance...