Dan Wallace has filled a need for the faithful who derive joy from studying the Fathers in their original Greek with his offering A Reader's Lexicon of the Apostolic Fathers. This is a Kregel publication and would be an excellent resource to have in Logos format.
Do we even have the latest edition (3rd) of The Apostolic Fathers in Logos? (http://www.amazon.com/The-Apostolic-Fathers-English-Translations/dp/080103468X/) The info on the Logos resource seems to suggest it's the 1999 edition, not the 2007 one. Wallace's book is intended to be used alongside the 3rd edition. Not sure it'd make a ton of difference, but something to note.
Also, from what I hear, the reader's lexicon for the Greek NT in the same series (apparently) is also quite good. (http://www.amazon.com/New-Readers-Lexicon-Greek-Testament/dp/0825420091/)
I have the undead tree version of this, and it is very good.
Donnie
