My wife and I are looking for types of bamboo (prefer running) and/or small trees for an 18"w x 24"d x 180"L planter.
This bamboo would work in your planter. It is upright and could be pruned to the height you want. It also spreads by shallow roots which would be easy to find and pruned to keep the plant under control. It is a vigorous plant so you would have to be diligent to keep it under control.