You guys are great! Now I feel like I have "some" knowledge when I go to get my bike tomorrow and pick up a mirror. More opinions and preferences are still welcome on this subject....

One type mirror I can rule out though--
I will have bar end shifters like this:
http://cyclofiend.com/cc/images/cc02...0009%20(2).jpg
so those little mirrors that fit into the bar ends won't work for me.