I was relating to certain Ruud fixtures, which specify 105 (or is it 150?) wire for the terminations. With HID, it's one detail to look for in the instructions!
As for appearances. well, you play the hand you're dealt. Strut can have a neat, if 'industrial' look. For a true surface mount, you'll have to arrange that before the inside is finished.
No matter how it's done, toggle bolts are almost inevetable- and I've never been really happy with the large hole necessary for the toggle- I worry about moisture getting in. Maybe I just worry too much.
Another approach- where the inside is left open- is to mount a bracket box to one of the steel purlins, and runs a piece of running thread out the back of the box and into the back of the fixture.
