Trees, Shrubs and Conifers: Shrub recommendation, 1 by Pseudo

Pseudo wrote:
Some time ago I posted about a White Pine I've got that suffered two consecutive years where wet, heavy snow stripped off several branches. This tree is recovering nicely, but I'd like to smooth out the lower roughness by screening the trunk. My initial thought was to plant a slow growing conifer, but it has been brought to my attention that this might not be the most effective means. I'm now considering a large shrub to accomplish this.

The site is shady, getting less than four hours of sun. It's well-watered and will be mulched as part of a bed that will tie-in the pine, small Japanese x Korean maple, and the shrub to be planted. Any suggestions?