New Landscape going in, questions about plants

Having a tear out and reinstall of our front, side beds. The older beds need work, the shape is nice, but needs soil work, needs to reclaim/refresh rock border installed around drip edge, and new plantings. Have agreed with local company to do it, recommended plantings were Dystilium in the back of the beds, with soft leaf yucca in front. Really liked the design and the ideas, but after looking at the yucca not sold on it 100%, it seems to look pretty woody after a bit, would like an option or two of some type of evergreen type plant, that stays about 18 inches tall and doesnt spread too much, plan calls for 27 of them, so it is would be a pretty big swap out if we changed out sooner rather than later.