Check good piercing parlours. They often have a decent selection. Halo is a favourite of my wife's although a little pricey at times for what you get - don't know if they have an online presence though.
Alright, I have been waiting for a thread like this for a while. I have some ideas, but only for guaged piercings unfortunately. My ears are 8 guage, which isn't horendously big but still opens up a lot of cool options. But you are looking for regular size jewelry, right?
I live in Santa Cruz where earings are big on men and women. It is my favorite thing about the city, style-wise. Everybody has earings.
I think the basic size for an ear piercing is 18 G. This company does really high quality stuff and the rings go down to 18 G. Not sure where you can get it online. They are based here in SC so it is everywhere here.