I just put my four 100W panels where I wanted. Drilled a pilot hole and used 5/16"x1" lags. Put butyl tape under each roof clip and piled on the self leveling caulk. I also use clips like these
https://www.grainger.com/product/426...B&gclsrc=aw.ds
so I can remove the panels quickly to clean under them and re-caulk if needed. Panels have been on the roof for a little over 2 seasons and over 7,000 miles with no issues.