The best, easiest and most secure way to do this would be for Q to become a board owner himself.
Q should create his own board via 8ch.net/create.php. Once the board is secured, he should edit the board settings and enable the CAPS ONLY function. When that happens, only moderators can create threads. Once he creates a thread, he can then lock it so only he can post there. In this case, he won't lose the board because it's explicitly for data dumps only (there are many boards like this on 8chan, like PDF libraries, personal blogs etc.). Discussion would continue on /thestorm/ or any other board of your choice.
If you need help setting this up, I'm all ears. No need for private communications whatsoever.