TJ,
I would recommend using the resources of the Nebraska Forest Service.
I have had great success using the Kansas version.
You actually have a district forester. Get the contact info for that person from the website and ask about using a treespade on cedars.
IMHO, planting 3-4 cedars/hour is a glacial pace. I would recommend putting a rototiller behind a small tractor and preparing the entire planting area for the shelterbelt row.
For tree seedlings, go to Topics on the website, then Trees To Plant. Click on the green "Order Trees Today" button. Click your district on the state map. It should direct you where to pick up seedlings in your district. I think cedars are $0.85 each in your district.
You and some kid helpers could probably plant 100-200 in a day. They probably will not grow very rapidly in the first year, but should do very well after that if you have good soil and water.
As to your existing cedars in the "wrong" place - they are literally the easiest tree to kill. Cut them off below the lowest branch, and you should have close to a 100% kill rate without the need to use any poison. (I would leave them, and cut them for pond structure as needed.)
Best wishes,
Rod
