Some recent photos:
A more traditional (single) long-handled halberd
The latter is sometimes translated as ‘hook blade spear’ – I know a Shaolin set for it as taught by Grandmaster Wing Lam.
The twin halberds are very different. I tried them as substitute weapons in the double maces (or double batons) set from Chen Family style Tai Chi Chuan. Aside from balance and weight problems with the weapons themselves, there are some moves where they are not just suitable. Among other things, the twin halberds have an axis of preference when comes to blocking and striking.
According to a reply to a post in May 2012 on the Kung Fu Magazine site, someone at Swindon Kung Fu in the United Kingdom asserted “The Nam Yang white crane guys use them in the manner of an axe”.
If anyone has heard of a set from any art for these weapons I would be thankful. A link to a recording would be a pearl.
LATE FLASH – some answers from the wide world
Gene Ching of Kung Fu Magazine wrote “You’ll find shuang ji (twin halberd) by Ding Zhifei on my DVD Shaolin Trips: The First World Traditional Wushu Festival. It’s the complete set, five demos in within the Competition section.”
It doesnt looks for me like a Southern set, but at least the weapon you are looking for. I have seen John Barbary performing a Southern Double Axe Set.