Are you designing the railing system/mounting solution yourself, or something you have seen elsewhere?
Designed it myself, and will build it myself. Aluminium equal angle 50.8 x 3.2mm, rubber blocks under aluminium pads bolted through the roof, and plenty of polyurethane mastic, although the rubber/ally pads should provide an effective seal, its always good to use some decent mastic just to be sure.
Idea is to keep the height of the panels below that which is required for planning permission.
Well that was a long hard days work, but my brother and I have successfully installed the two cables, still have some internal tidying up to do, then just a trench to dig and get the cables into the garage. My 43 meters of 25mm SWA actually turned out to be just over 50 when we measured it, so plenty of cable.