Edit to add, I've done a few Googles and know I'll need masonry bits but the hammer drill seems like overkill for perhaps 8-12 small holes. Thinking of drilling away from the grommets and using short bungie cords to keep tension?

Guessing someone here has done something similar?

Thanks!

Wes

make sure you drill into the mortar not the block itself. You could crack it. Use concerte anchors

Thanks, that's along with what I was thinking. I figured I'd need some sort of hardware such as the bungie cords for tension but haven't gotten started yet.

Wes

Tapcons in wither the block or the mortar joints should be fine.
Drilling into the mortar joints will be stronger.
Use at least a 1.5 inch screw.