Well, I got a Rola rack Tuesday and finally made some mounts to mount it lower than the cross bars. It sits 3/4" above the center of the roof line. We had some channel iron, so I welded up some L brackets, then welded the channel iron to it, so the rack sits inside the channel iron and U bolts keep it in place, I eventually want to weld the rack to the mounts, but I may do some adjusting to the height.
I just ordered a 40" spot only light bar for it. I'll have to take it down in weld some tabs on it for that, so I'll go ahead and weld other tabs for miscellaneous lighting around the rack. I'll probably weld the whole rack together also...I'm not a huge fan of the way they're supposed to be held together by screws.