Yeah, ignore that comment, I misread your previous post and thought you were saying that using the 50amp breaker would be of benefit becuas it would reduce the draw to the main relative to the 2 20's, but now I see you were just talking about having those extra 10amps as a buffer, or if I want to increase the number of lights.
I'm definatly not going to increase the number of lights at this spot, as I'm already worried about using up too much of the power from the main. One thing I omitted earlier is that there is an oven that will occasionally be used as well, different breaker, obviously.
Is there any way to actually test how much draw there is on the main? If im going to be using ~30amps for the lights that still leaves ~50 for the rest of the appliances before I hit 80%. Can I go turn everything in the house on and check the draw before I put in the lights?
Also, worst case scenario, I can always run 4x1000 and 2x600 which should reduce my draw by ~5 or 6 amps.