What I've learned is that names are as diverse as the people and have different origins that may be regional, religious, ancient, or contemporary.
Most of the names that we see on list seem to be the more common Amharic names. Still their other names that are Tigrayan or Oromiyan in origin. Here is a quote from the EthioMed website. If you've never check out the EthioMed site it's worth a look.
Traditionally, the father picks Oromo children's names but the mother has great influence in naming the daughter of the family. It must also be said that Oromo names have meanings as if to convey wishes of success, wisdom, and prosperity through generations. For instance, the most popular Oromo names are Ibsaa for males and Ibsituu for females, both meaning "light".Some names are common Amharic phrases. Some names are Christian or church names; Hebrew, Jewish, Arabic, or maybe even Ge'ez. The origin of the name accounts, at least in part, to the difference in spelling. I'm not an expert on Ethiopian names of course but this is information that I've gathered over the many months of reading. I recommend reading this interesting article on Ethiopian naming.
If you can't find a name looking at one of the naming list try a Google search. But add a qualifier and instead of searching "Ethiopian name XXX", try searching "Tigrayan name XXX", "Ethiopic name XXX" or "Ethiopian Hebrew name XXX".
Check out the links on the right. There is an Ethiopian naming book you can order and here are few sites that I've found that have smaller list of names.
male and female names.