Where to buy a Possum Box? ...

Regarding germination of a mango nut?
Answers:    You might look at your local agricultural center or you can get them online.
http://www.wildlife-traps.com/possum.htm...

Or, you can build one:
http://www.nana.asn.au/n2-pbox.htm

Good Luck
What is the best method to prune a...
What within the world is a possum box? Is it something that you bury them in? I would regard that if you were going to bury them that any antiquated shoe box would work. Are you talking in the region of a trap? Most hardware stores will have live traps.