I have the same planters and have lantana (pink/yellow) in mine. I used to live in CA (SF Bay area) but now live in Maine 5B. I do have to replant every spring but I love how they look. Grasses would look nice as well.

My tip will be to fill the bottom half of the planter with a "filler". I have used many things in the past, but now I use pool noodles. You can easily cut them to size and they are cheap at the dollar store.

Depends on where you are going to put them. Is it sunny or shady? Do you want grow flowers, veggies or just foliage. Perennials or annuals...

I am open to flowers and foliage!!! I have both sunny, shady and partly shady options !

Veradek planters usually come with an insert that you can put in to limit volume. Personally, if I lived there, I’d fill them with Dendrobium kingianum or cymbidiums. Maybe cyclamen, begonias or fuchsias. Maybe Primula malacoides or succulents or Cineria. depends on how close to the coast.

I don't think having more volume is a bad thing. So you know what is the capacity of the containers in gallons? Your choices are essentially unlimited. You could have roses, hibiscus, Mandevilla, jasmines...I like Mandevilla/dipladenia do non stop blooms, Jasminum grandiflorum for great fragrance. I haven't grown hibiscus but I think they do bloom for a good part of the year. Roses require more maintenance and bloom in flushes so not constantly in bloom. Most of these will be perennials for you. Look around and see what is growing and blooming around in your neighborhood, what you like, stop by the local garden center..