Can tell you want to use the light rail. Have a light rail and a 5x10 tent. First try went with two 1000w hps, too hot for me, used a 8" axial to vent, with speed control. Was able to finish grow and got some nice stuff, far from my first grow but thought temps to hard to fight(out in cali, saw tent sucked down by such a fan). So removed one light and put in light rail.
Now my tent is old enough to have plastic corners, every top connection broke under constant moment. Was able to rebuild using 2x2 lumber, but removed the rail. Still think it was combination of vibration and temps.

Know that new models some have gone to metal corners, think they were aware of problem.

Since have gone to one 1000w hps on top, and two 4'fl + two cfl' s on the ends. Temps down, no vibration & plants seem to enjoy. Attachment 297113