6 bulb unit here and used these in my ceiling.
https://www.homedepot.com/p/E-Z-Anco...5310/100040265
The screws they use are small enough they fit right inside the cylinders ATI uses for hanging, and the cylinder head is large enough it hides the plastic. Each one is rated for 75lb, should be plenty strong enough. Been holding mine for a little over a year, and I move them up and down weekly for maintenance.