Due to the recent prevalence of diseases and pests with Leylands, I would hesitate to suggest them. The preferred substitute, at the moment, is an arborvitae, either Thuja plicata x standishi 'Green Giant' , matures at 30-50' x 10-20', or 'Steeplechase', which is supposed to be an improved slection of 'GG', or T. occidentalis 'Smaragd' (a.k.a. 'Emerald Green' or 'Emerald Beauty'), maturing at 10-15' x 3-4'. Which you choose is up to you, depending on how tall you want this barrier to be. There are also several other cultivars of Thuja which should grow to be good screens - check and see what is available in your area.

There is also, since you will want a LOT of trees, the option of checking with the NC Forestry Dep't - they will have a variety of trees for sale, at a good price for quantities - fairly small, but they will grow the faster with less care. I am not sure what they would have available for when - it may be that the greater selection would be for spring planting, but you should still be able to plant through the beginning of Nov..

Depending on your location, almost any of the pines should work, as should a mix of deciduous hardwoods and conifers - which would be less of a great green wall, and more like a 'natural' forest, especially if planted in staggered rows of two or three or more.

You want to build a great wall of China around your acreage?
WHY?!
Mark off some areas to specifically NOT mow them, after a relatively short period of time you will have a substancial amount of woods growing there. It's nature's screen and it looks a lot better than a giant hedge of trees. I can understand needing a tall narrow hedge on a small property where the houses ar right on top of each other and there is no privacy but on a lot the size of yours it doesn't make sense.

If you decide you don't like that idea and prefer the man-made look then screening alternatives might include Japanese Cedar, Green Giant Western Arbovitae and virginia pine (forms a better hedge than other pines IMO) and southern magnolia. At least try to mix it up.

If you have 10 acres, a "solid" wall of screening is not so necessary. Considering contacting the department of forestry and getting some cheap seedlings of several different things. Loblolly pines, was myrtle, white pine, and deciduous hardwoods. Create a diverse mixed screening that will benefit the environment, be less susceptible to disease and be far more attractive than "soldiers in a row".

You'd be surprised, seedlings can grow very fast. And some seedlings are big, the wax myrtles that I got were 3 feet tall and only cost 50 cents each when purchased in bulk.

Mixing in different trees into your visual screen is often mentioned not just one species, particularly when long distances are involved.
Other possible mentions for screening are Eastern Red Cedar, holly, live oak, and bald cypress (deciduous). Recommend using native trees for the bulk of your plantings as they will normally be successful with little care after first year. Save the hybrids and exotics for up closer to house and/or specimen trees.
Mixing in some deciduous trees in with the evergreens leads to a nice effect and can still be a fairly effective screen.
My wife planted 10 Leylands as a sceen. They were planted in groups of 3, about 10' apart. Other trees used included bradford pear, cedar elm, ash, magnolia, and live oak, as well as crepe myrtle. The effect was ok as the Leylands were blended in with the other trees.
I spent about 8 hours this year cutting bagworms from those 10 Leylands. I hope next year it is not worse. Am thankful I didn't have to cut bagworms from 76 more Leylands. Leylands are not a trouble-free tree.