RE: Using a 2 row planter?
If you cut the plot this fall, it will let some of the residue compost over the winter. But in the spring you should disk and if possible drag the field to get a fairly smooth bed. The planter will work better and plant at a more consistant depth. About 1 inch would probably be a good depth to shoot for. (I've planted corn and Cow peas slightly deeper, trying to foil crows and other birds.)On your top link, an adjustable one will help in keeping your planter level and also help in keeping your seed depth even.
Russ