Hi Jane. This will be my first post though I have been a PBS member for several years. Your message spoke to me as I too have a US home as well as a winter home in Zihuatanejo, Guerrero, Mex. We have found that a number of bulbs grow quite well there, the best being several species of Hymenocallis and the same for Hippeastrum. As sources go, we have always relied on our local viveros who are extremely knowledgeable and happy to talk to and supply those with a rather intense interest in botanizing. Especially around Xmas are more things available of interest. Most commercial items are coming down from Cuernavaca. I would also check Mercado Libre (Central American equivalent of ebay) on the internet. We have used it successfully, though not for plant materials, a few times. Can't answer your question about A. spiralis--perhaps someone else... Good luck with the search for good plant material and feel free to PM me. Cheers, Ray