I have a post hole digger on my cut. I would guess a hole takes me 10-15 minutes to auger. That is 4 trees an hour. 8 hours a day is 32 trees a day. 200 trees means the last tree would be dead before I got it planted.
I was involved in a "tree day" at kids school. They dug the holes with a back hoe. Dig a hole, drive the stakes, back fill to height, drop the tree so it is 6 inches above grade, backfill to rootball, cover with mulch, tie to stakes, move to next tree. The kids had a great time. The school got a bunch of trees.
My vote would be a back hoe. You could probably hire a local backhoe operator to dig 200 holes for less cost than purchasing a post hole digger and all the trees would be planted. Then again, you could always just convince the CFO that you needed your own back hoe /forums/images/graemlins/wink.gif