Ok, after research I did, its not easy to get these books from a Greek online general bookstore due to their low demand... :(
However you can contact the editors of the books and have them sent to you separately, or, even better, find a bookstore that can provide you with all the books from all the different editors, in order to keep the postage cost down.
So here are the editions and contact information for them:
Edition "Marios Verettas", Tel: 0030 210 33 05 139,
www.verettas.gr/:
"Mega Onomastikon", ISBN 960-7756-02-9
"Mega Hetairikon", ISBN 960-7756-14-2
Edition "Georgiades", Tel: 0030 210 38 36 231,
www.georgiadesbooks.gr:
"From Gaia to Hypatia, the Greek women of the ancient world", ISBN 960-316-288-4
Edition "Kyromanos", Tel: 0030 2310 28 24 27:
"Homeric Onomatologion", ISBN 960-7812-35-2
Edition "Eleftheri Skepsis", Tel: 0030 210 36 14 736, 0030 36 30 697:
"Thesaurus of Greek names", ISBN 96-7931-65-3
"New Lexicon of Greek Mythology", ISBN 960-7931-28-9
Edition "Kypeiros-Parousia", Tel: 0030 210 38 29 833:
They did a fine reproduction in Greek of the
"Lexicon of the Ancient Mythological, Historical and Geographical Personal Names", N. Lorentes, Austria, 1837
now under the ISBN 960-86714-4-2.
As I said, it will be nice if you can get all of these books from one bookstore, so you can keep the postage cost low. I am pretty sure that "Marios Verettas" and "Eleftheri Skepsis" will be able to provide and send you all those books, so try to contact them first and ask about that.
Enjoy your reading!
"Until the day that an ancient inscription will be found with the name "Alexandrovski" (or "Alexandrev" or "Alexandrov") written on it instead of "Alexander", true Macedonia and true Macedonians will remain Greek, as they always were."