I have regular mirrors on both sides (chrome) but I also have a peep mirror on the drivers side and that's because I have a side mount spare tire. My understanding is that the peep was a popular add-on because it helps you see above the spare. I never heard them used as an 'instead of' a passenger side mirror.
Tip I got from someone here on the 'Bolt: Once you put the mirrors on, brush a little clear nailpolish on the screws. The mirrors may be stainless but not the screws and they rust up real fast and look like crap!
You can check out my mirrors on the Gallery or at the link below.
