Using steel...nifty trick I learned from the builder. Stack several sheets of your material on a suitable support keeping the ends even, measure your screw locations (spaced according to your rafter/truss distance and next to each major "rib" on the steel...3 as I recall on a 3' panel) then use a pointed punch and hammer to form a dent. Hit properly you'll see the dents through several sheets. When the dents start to get faint, add new sheets under the dented ones and hit them again. He was in the business for years and apparently "drilling" was not only time consuming it led to premature rusting (for him meant "warranty" repairs) because of the heat from the drill bits. The added benefit is you measure once and can be assured of the holes being in a straight line (assumes your building is square and your trusses/rafters are set properly) with no chalk/pencil lines. Now for the part I forget...I had the builder install 2x4's along my 40' run, 10' from the side walls to serve as "nailers" for the lighting. As I recall they were installed on the top of the bottom cord and we used long screws on the lights to get into them. The only other thing I can think of is you will need small pieces of wood to mount any fixtures...the "ribs" on steel stand about 3/4" high from the panel. No big deal...just something to think about.
