This seems to me the easiest way to do cross server card trades. You follow up this posting with one of your own telling me that you want to trade. In this posting, tell me how many cards and which toon to receive the cards on this server. Log into Khyber, create if needed an account. Works best if VIP and iconic heroes. Run a solo quest if you lack coppers for mail or send my toon (Redjokker) mail asking for funds. Might be quicker to run solo quest. Generate cards if you have not already done so.
Send to my toon Redjokker, your cards. Inform me in that mail which server you are from and which toon you want me to send you your cards. This should match what you posted. Within 24 hours or so, and probably much sooner, I will log into this server and send you the same number of cards I have already generated, plus today's roll if needed. If for some reason I receive more cards than I can send, then I will continue to log onto this server and generate cards till even. I will check here before sending cards to make sure everything matches. This thread will also be a record of the transaction if there are issues.
I have two VIP accounts toons here. One with 9 cards and other with 9. This is on a first posting basis, and if several players wish to trade, I will do so on order of who posted first until I run out of cards. I would rather send all cards at once rather than two here, one there, etc.
UDATE: 17 cards available here for cards on Khyber.