1. Will it be in sun or shade?
2. Do you want deciduous or evergreen?
3. Do you want to trim/shape them regularly? (A few shrubs look fine in natural shape; many require require regular trimming to maintain a hedge shape.)

Hi - thanks for responding. Here are the answers ...

1) Shade in the morning; sun from noon to dusk
2) I guess evergreen as we'd like full bushes all year
3) Yes, the bushes will be trimmed regularly

Cocoplum or Orange Jasmine grows well as a foundation plant. Use the Crotons as focal points and not as a hedge in front of this foundation. Consider Bromeliads as a ground cover between the Cocoplum or Orange Jasmine.

Viburnum suspensum can be kept down to 3-4 feet without having to have a lot of width. Green or variegated pittosporums are good but they tend to be a bit fatter when your looking for four feet tall. Some var. pitts will give you a decent color besides just green and that gives you a good chance to put something in that is red which will stand out well. A lot of crotons could give you that color. Do you think it is too sunny with all afternoon sun?
I like the bromeliad idea too. Cherry Coke Dyckias would be dark red in that sun and they took 17F without any damage. They are some of the only bromeliads that flower and don't die after they flower. Those would be pushing 4 foot tall flower spikes in another month.

Thanks to all for the suggestions - I found an older pic of the area needing the bushes. The thin Burford hollies were in place at that point and got progressively thinner as time work on. Just to be clear, there is a 10' area on either side of the flower planter to be filled. Someone outside this forum mentioned podocarpus as a solution as well. There are also crotons in place now closer to the front walk.

Exactly what direction is that wall facing? Are you wanting to fill the whole planting area within the concrete? I already notice in the old picture that the hollies on the right were already looking bad compared to the left ones. I was wondering if it was how the plants were shaded under the soffit area, or not. Is that a windmill palm you have on the left?

The wall is facing WSW and yes, we'd like to fill the wall on both sides of the planter. The plants under the soffit are shaded for part of the day until the sun creeps over the house in the afternoon.
And yes, that is a windmill palm at the front left corner of the house. Thanks