The problem might be the wind and its effect on an evergreen... How is the wind exposure in that spot? I know that I get most of my worst winds out of the W and NW and that can end up dessicating the needles on the small leaf evergreens or browining out the larger leaf types.

What might help is putting up a lattice screen and then perhaps putting evergreens in front of that, with the lattice helping to knock out alot of the prevailing wind. You might alternately consider planting a vine like a clematis to use for screening... and if you chose a type 1 clematis, those maintain the main stems and offshoot vines (blooming on previous growth), which can then be trained against the lattice for a permanent screening. Even the type 3, which gets cut back each late winter, can easily grow to recover the lattice or other support.

Resin containers work well and are lightweight. I have my largest shrubs, a tree, a clematis & a wisteria in that type. Most of the rest of my shrubs and perennials are in the larger (14"/16") foam containers and they have held up well so far. I have a few other shrubs, perennials, and bulbs in smaller plastic containers and those have also held up so far.