Neither on Mexico, but just get a american credit card and you can buy the ebooks. I have a american subscription to itunes, amazon, etc. Usually international versions sucks.
On the other hand, the mini reader looks great! If you have a iphone or a ipod touch you can get the kindle reader, the barnes and noble reader and the best one, in my opinion stanza, now owned by amazon. The 3 of them have public domain books, and the readers are free, maybe you can try them out before making a decision anfter exploring the content of each of them. I do not think amazon will ever delete a book ever again, after all the bad press the got, and now they are compatible with pdf.