Here you can use this to mount right to an aluminum plate to your camera tripod. As you see the assembly simply screws off so you don't even need to get the screws, just drill the right size holes diagonally and mount. Diagonally the fixture measures about 5.7" or 4" square so the top aluminum strip (that holds light fixture) should be at least 7" long, bent 2" high and I leave 7" again for bottom.
Sun System Socket Assembly 15 Foot:
Speedy Metals 6061 aluminum strip 1/8" x 2" x 16" for $3.20:
Sun System Socket Assembly 15 Foot:
Speedy Metals 6061 aluminum strip 1/8" x 2" x 16" for $3.20: