If you use grasses you'll have at least some part of the year where the utility boxes aren't hidden -- after you cut the grass back in late winter or early spring, and until they are tall enough to hide the boxes.

Panicum virgatum 'Cheyenne Sky' (switchgrass) is a shorter cultivar of the native switchgrass that might work for you if there is moderate moisture. It holds together for me pretty well through the winter, unlike some other grasses that don't stay as upright. Mine are around 3' tall once the stems are up, but the grass itself has some height as early as mid-May. Nice red colors in the fall. It's small enough that you'd want several for that situation, but for me that would be preferable to planting one or two of some huge thing that is going to be harder to maintain. Lower perennials of some type would be nice planted around the grasses, and possibly bulbs for spring interest before the grass gets going.

The other two beds are tough because of their size, especially the really narrow one against the house. If it were me I'd consider enlarging the one at the corner of the walk so that you'd have room for a few small to medium size shrubs. If you keep it the size that it is, be careful to choose things that stay small. We had a bed like that in the house I grew up in, where there were a couple of small juniper shrubs. By the time I went off to college we were having to do a lot of pruning every year to keep those monsters from blocking the walk.

You might try posting your question about the beds to the Landscape Design forum, where they frequently take questions like that and there is more activity.

Karl Foerster is a nice tidy grass that stays upright and doesn’t get too big. It will be bare in spring but not for long. The stalks do quite well through winter but do need to be cut back before new growth appears in spring.