I have a few recomendations
canadian Hemlock weeping form
Tsuga Canadensis "Pendula"
Takes shade well, is native to your climate zone, actually prefers part shade looks good as an informal hedge and also takes shearing and shaping well. Slow growing. Trends to getting wider than tall. A little bit expensive in common best sizes, but takes fewer to create the hedge
Be certain to get the "pendula" form for the other cultivars will not maintain the 6 ft height you ask for.
Taxus x Media "Wardii"
Nice dark green dense color takes a formal shearing very well and handles northern winters with heavy snowfall very well, without splitting. Like all Yews, it takes anything from full sun to full shade, becoming a bit less dense in part sun to full shade conditions. tends to grow as wide as tall. This means you may need fewer of them to do what you are wanting to do. They are also very very inexpensive.
Chineese Juniper 'Sea Green'
Juniperus x pfitzeriana 'Sea Green'
should also do well.. might be a little diificult to find but again does well as a hedge. may or maynot show distress on the shader portions of your hedge.
With broadleafed evergreens, cannot do better than the Hollies
They do not suffer the winter kill that Rhodies can undergo during the windy winter days and nights. they provide nice winter color and nice foliage during the summer
They shear up into a formal hedge very easily but likewise make a nice informal hedge so long as you can do occasional pruning to remove what I like to call "Wild Hairs" branches that are growing far too tall or quick.
they have beautiful red berries of course, are very inexpensive, can be fairly quick growing but very easy to keep to height.
I recommend the "Blue Prince" and "Blue Princess" They take cold and wind and even half shade very well. Deep blue almost purplish foliage
does not winter burn much if at all. If you decide to go with the hollies, you will need the "prince" to polinate the "Princess"es. One prnce has enough pollen to polinate 100 princesses but they do not make the pretty berries. I have often advised one of two methods, either do the entire hedge out of the princesses and then stash a prince somewhere else on the property wher the lack of pretty berries isn't an issue OR place a prince on each end of the hedge, keeping it all symmetrical
I hope this wan't informational overload LOL