The 2 row planter in post #1 is what I would use here in our ground and the conditions I have thought of using it.. That being more a "food plot" type of planting in our big pasture..
In our growing zone 2 part of the bush we don't have enough time to get a crop of corn, dent or sweet... I would just let it grow to where it was able to achieve during the season, brush hog or cut for a fodder type feed for our small livestock... Good enough, with all parameters considered..
How I envision using the planter is move them as close together on center as possible, even if I have to switch side with the planters.. This to plant 2 rows about 6" or so apart.. This will maximize the amount of corn in the area given, still leaving room for cultivation... Or..... To do this, it may require running 1 planter about 3" off center and going over the same row 2 directions... Maybe not the most productive way to use the tools and seed, but again, good enough considering all parameters here in this area...
There are a number of people that buy planters and fab them into 1 or 2 row impliments... Things like JD 71 planters and the like.. They are not shy about charging for there work...