According to this page
http://www.ngcontrols.com/wd1.php
The base unit comes programmed for 1000A rated output at 160V, and is user-upgradeable to 1200 and 1400 amps and 260 and 360 volts. The WarP-Drive comes from the factory with CANbus connectivity, which gives it endless capabilities to operate in conjunction with already-in-development third-party hardware solutions.
However, they don't specify how that user-upgrade works. It could be software settings, or it could be modules that are piggybacked onto it, or replacing the power module keeping just the brain, etc. I see nothing on the site that explains it, nor prices for that on either the classic or industrial versions. (there is a price sheet from 2012 but it doesn't list any upgrade pricing, just base units and accessories).
But AFAIK they don't deal with end-users directly, so you'd have to go thru one of their authorized resellers
http://www.ngcontrols.com/authorized_resellers.php
All the distributor pages I found in a quick google search only sell specific model controllers, no upgrades (not even mentioned). I didn't look thru the list above for it though.
FWIW, it would be odd to sell a controller like that, unless all of the models cost the same, because the hardware to go that much higher in voltage and current would be quite a bit more expensive than the lower power setup.
They'd have to charge everyone for that hardware, even if a particular buyer isn't using all it's capabilities, or go broke. (or sell all versions at such a high margin that it wouldn't matter).
So while I am not familiar with Netgain's controllers, it seems unlikely that a simple software "unlock" exists for them, though it is certainly possible that they do have setup software for them that changes their HVC and/or LVC, and their current limits, but probably within a narrow range based on the particular hardware limitations of a specific model or series of controllers.