Howdy George,
I got the Leinbach 20" x 20 notched disk. I am very happy with it. When researching disk harrows, I looked on Leinbach's web site and they can be ordered with the smooth disks. I suppose you could do that, but you would have to wait until it comes in at your dealer with his trailer load order...which may take a while.
Just knowing you from your past posts and property, (planting wildlife food plots, and such), I would go ahead and get the notched disks. It would work better on rougher ground. I bought the Leinbach because it is handcrank adjustable and good value for the money.
Pic is when I first got mine and the paint is not worn off the disks. Won't mention who the good lookin' fellow is.......(and no comments from the peanut gallery)....