Boxwood is a very common hedge in the Chicago area, also yew, usually trimmed into a box or simple geometric shapes. If that is what you want it's pretty easy. For a small suburban yard that might be the most appropriate, though not much fun. I like mixed hedges, so I might use holly and yew, the contrast of color and texture is more interesting than a solid wall imho. Larger rhododendrons could also work, or mountain laurel if you are willing to have a more natural look, not a sheared rectangle... maybe a hemlock or two for upright accent if you have room. The rambling, woodsy look can be lovely if you have space and a less formal setting. Mix a few flowering shrubs in as well, and stager the planting a bit, rather than a singe straight row. Junipers are nice in full sun, but won't stand shade or crowding as well as the others.

Not sure this thread is at all related to fruit growing, but I think it is neat that you've got a conversation going⦠which I will now add my two cents to! Holly and possibly bamboo might not be the best bets if you're in a more arid and windy part of Kansas (ie. Western). This is just based on my experience in NM and CO. Bamboo does not do great in the wind, and can be damaged by zone 6 winters. It can take forever to become established enough to be useful as a screen in any exposed site. You probably have not seen holly planted there because it is a more mesic plant generally. The only broadleaf evergreen that I can think of for your location would be silverberry, Elaeagnus pungens. It also has edible berries and is a phenomenal honey/pollinator plant. Otherwise you're looking at any number of evergreen coniferous trees and shrubs such as thuja, junipers, cypress, and yew as you mentioned.

I know the meserve/Blue hollies are Japanese Holly hybrids, and Soft Touch is a Japanese Holly cultivar. The Merserve/Blue hollies (which I've planted) look great in Zone 6 winters. Fully evergreen, and have red berries to boot. Not sure how they would deal with Zone 5...that's pushing their limits. They grow pretty slowly and take well to pruning...so you could probably maintain them at two feet fairly easily. Not as sure about one. Would be a lot of work...but so would Boxwood or anything else. You aren't in New England. Are Boxwood psyllid or boxwood blight problems in Canada? The other standard hedge material is Yew...that may be more cold tolerant. Dwarf Golden Japanese Yew (Taxus cuspidata 'Nana Aurescens')?

Beyond that it's anyone's guess. It's not as simple as tree A will live to age X and tree B will live to age Y. Trees also don't just stop growing at some designated height or spread. You can find averages for these aspects, but while I'm pretty sure a parrot will outlive a dog, I don't know how old each will be with precision. I'm not sure what your goal is ... you said you plan to recommend these trees to lots of people. Are you trying to landscape a subdivision or something? Are you wanting to plant a single type of tree in every site? What is this list for? I'm not familiar with tons of varieties of evergreens, but whether something can come down without climbers or bucket trucks isn't solely dependent on size. The neighbor's last ailing tree (40'ish cherry) could have been dropped across our yard ... if we didn't mind it destroying our perennial garden and cobblestone paths; a bucket truck was brought in. Their current dead tree (50'ish hickory) is capable of hitting houses or wiping out the street, or it could kill several other trees on its way down if felled ... it will also need a bucket truck. The 35' branch that had to be removed off one of our 75'-100' white pines was removed by suspending it off of the pine itself and two nearby oaks and lowered (thankfully not just dropping on all the understory trees it was looming over). There were aerialists and a little vehicle (pulled lines and hauled log chunks) but not bucket truck on that removal. Our Eastern Red Cedar is about 35' tall and it was probably 20'ish in the early 80s, no idea how old it is, but we do know it's been hit by lightning twice (and had its top reshaped). Every mature tree on our property, except the serviceberry, requires an aerialist or bucket truck to prune. For a while the Bradford pear (no commentary on its existence, please) could be pruned with a pole, but it needs a bucket truck too now that it's probably 25'-30' tall. It was the last holdout. So I wouldn't count on any tree never requiring a bucket truck or climber. The birds love our yew shrub (we hate our yew ... though if it didn't have to be pruned multiple times a year/was in a different spot it might be more acceptable). They also love forsythias and quince, though. There's definitely nests in the cedar, and I'm pretty sure several of the oaks, maples, and cherries have nests in them. It depends on the bird what tree they'll build in. One word about hedge style planting, my grandfather planted a hedge hemlocks, and they were great and beautiful until one in the middle had an issue. It's nearly impossible to replace a tree that's 25' tall and planted tightly, and the two on the sides of the hole lacked green towards the hole because they had previously been growing into the missing tree. I don't recall whether they took down the whole hedge or moved and the next owners did it; the hedge no longer exists. Price of tree ... what's your definition of small?