sorry for the very late reply. It looks like you have quite some resources here. It would be good I think to start with Gonda's grammar (like it says: a concise grammar) and the exercises. I am afraid, however, that only from the beginning of June I have enough time to engage in this language exchange.
I seem not to be allowed, as a new user, to send private messages. Could you e-mail me instead on firstname.lastname@example.org
and give me your e-mailaddress? Also, could you tell me something about any useful Greek resources where we could start? Thanks.