Not sure where to find landscape photos of a project like that, but here's a link to coastal ornamental grasses from a Florida retailer.

Try:

Eragrostis
Muhlenbergia
Panicum
Leymus

There's a difference from the actual beach environment, sandy, salty, windy conditions, and making something look beachlike with sand vs mulch. Sand as a mulch isn't going to be sandy mulch very long. Beaches undergo constant replenishment and change. I think this landscape would take a lot of maintenance to remain the look that you're after.

Good luck!

Here is a link that might be useful: Coastal Ornamental Grasses