I also downloaded the map from Bionic Donkey. Like General Steiner, I live in Australia so I decided to get it printed here instead of having Bionic Donkey ship it over.
I got it printed on 5mm PVC with a matt laminate. The PVC is pretty flexible so it adapts if you have an uneven surface (for instance, if you had to put two tables together to have enough room for the board). The matt finish is to diffuse any glare on the board coming from over head lights (I have many over head lights downstairs where the board is set up).
The best thing about this board (other than the size) is that it has the unit placement marked on the board which makes it so much faster to setup. And I must say that playing on this board for a couple of months warps your perception of the original board. I look at that board and wonder how I managed to fit all the units in those little territories before. This big board is a luxury, and I’m spoiled.