This is the thing with posting such a question on a forum for mainly cannabis use, I'm not meaning to piss on anyones parade by saying this but that's a question best searched for in forums dedicated to mushroom growers, a simple search will yield good results, it's down to preference and experience at the end of the day, people always tend to go with what they prefer for whatever reason, start with the Mexicans and then try amazons etc.. You'll gain the experience which you cannot buy and you would of answered your question.
Although I have a passion for fungi I have mainly signed up to this site for knowledge, help, my grow log and then a decent contribution for when I can pass on experience.
Good Luck!