How can I get seeds for WHITE-blossoming Selenicereus grandiflorus sent to me in England or Kenya, please?

Phillip W asked:

In the USA the natural habitat of this climbing cactus seems to be only on the east coast of Florida. It usually grows up trees. If there are seed-exchanging groups who could help me, I’d really appreciate it. Perhaps there is a member of a cactus specialty group who could respond. It would be very difficult for me to receive either seeds or cuttings in Kenya, because of the bureaucracy here. It would not be illegal to send or receive them here, but the bureaucrats would want to go through all sorts of red tape, if it were cuttings that were being sent. Indeed, if it were seeds and the bureaucrats detected them in the envelope, the red tape would start spooling out, too. However, if seeds or cuttings could be sent to my address in England, there would be no difficulties. Thanks for whatever help anyone can offer. I loved these flowers as a child in Florida and now for the first time I am in a region where I can grow a white garden and have these glorious blossoms — in Kenya.