As EMB said the Amish use many Biblical names (such as
Naomi,
Lydia,
Esther,
Peter,
John, etc.) There are also other names that are popular among the Amish that seem odd to me, like
Barbie,
Sadie and
Rosanne.
For surnames, you say you've only seen 5 or 8 - I'm sure there are more than that, but I'm always surprised how few there are. The ones that come to mind are
King, Miller, Stoltzfus and Yoder. It would be interesting to know what percentage of Amish families have one of these last names!
(As a note: I'm in Pennsylvania and I know a few Amish families personally. It may be different for Amish in other parts of the county, like Ohio or
Indiana.)