i am no expert... just bought my first green tree 4 months ago biak locale. already she is tame and docile, more so then my carpet pythons. of course ive been bitten once or twice but all baby pythons are nippy. she is truly a joy to hold and work with. just came back from the vet with her for a check up on some broken teeth( missed her prey) and all the girls at the office were going crazy over how pretty and tame she was. personally, i dont believe in mean snakes and if a snake bites you and you dont freak out about it the snake will recognize this and stop biting all together. so my advice is to buy what ever locality you like the best. handle it a few times a week. wear gloves at first if u have to and in no time you will have a tame snake.
Jason