A promising start.
Oceanic Paradise World
Modified Vehicle: This Order has had to adapt their transports to new and different circumstances.
Considering the environment of the planet this Order is based on, I think it should standardize on the Chimera and other amphibious vehicles. Mount the Exorcist missile launcher on the Chimera chassis, restore the Hellhound and Devil Dog's amphibious capability (they share the Chimera chassis, but have a different engine)...
Modified Weaponry: When the Order’s forges produce a weapon, they produce them in a style that is specific to their Order. Examples: Power Sabre, Bolt Pistol with weighted butt for clubbing.
Power cutlasses make sense, if you want to give your Sisters a nautical (or piratical) theme. As for the pistol's modifications, maybe an axe blade at the front, for boarding operations?
By the way, will they field combi-spearguns or vehicle-mounted harpoon cannons?