I doubt the load warrior brackets will fit a basketcase. The basketcase is pretty simple. I suggest going to your local hardware store and custom building something to mount your lights.
It shouldn't be hard and it should be pretty inexpensive. (couple of "l" brackets mounted to the existing basketcase loops and you are done.)
I haven't actually tried it, but i "think" it can be done pretty easily - and it should be solid enough to hold on lights.
Not that long ago, I had two sets of Yakima crossbars and two bike racks mounted to my basketcase. This set-up worked with bikes, and since bikes weigh alot more than lights, I would guess that it should support lights much better.
Note: The weight of the bike with the rack in this arrangement caused alot of vibration on the rack and I have since taken it down - for safety reasons.Here is a picture: (hard to make out the details but it should get the idea across)