Their are certainly differences in growing preferences of various Alstroemeria species, and quite a few are from Brazil rather than the west coast of South America. I don't really know the varied Brazilian species as well, although some such as Astroemeria psittacina and its various cultivars do very well here in northern California. As to the alpine, desert or Mediterranean climate provenance of most west coast South American species, I think you are on your own. A tropical climate will probably defeat your best intentions, unless you can cool greenhouse grow these to give them the diurnal and seasonal temperature changes they prefer as their cue to grow and bloom. That is what we do with touchy high elevation plants from the Andes here in California that can't take our summer high temperatures. Are there in fact any Brazilian species that grow at low enough altitudes or high enough latitudes to be used in a Sao Paulo garden?

You should check out Mauro Peixoto's web site, www.brazilplants.com. He lists quite a few native Brazilian Alstroemeria species that he is growing, and I see that some are also native to the Sao Paulo area. He also lists seed for some of these as available for purchase.