Any others that are specific towards sponsorship?
Yes. Coptic Orphans allows you to sponsor a specific child. Also, you can sponsor a mission priest (and his family) through OCMC, including native African clerical families who couldn't continue ministry otherwise.
Edit: While it's not like sponsoring a particular child, one can sponsor particular programs with all of these Orthodox charities (including, for example, a medical clinic in Ethiopia, an Orthodox orphanage in Guatemala, an Orthodox home for abused kids in Romania, etc.).