I don't think planters is your issue.    ridge cultivators are....   as you know, they make a conventional cultivator (row cropper) look silly.


   I grew up with 3 16 rows and one 8....  Learned on the 8, then graduated to 40' cultivators....


got out of ridges.



Went to 24 row and 12 row stuff convnetionally....  Got into Navy's, tried banding then cultivating with 12 rows.....


I'd go with two 12 row.   Just seems like a tractor was made to handle a 12 row mounted ridge cult.....   16's work, but they will handle the tractor, where as the tractors handle the 12.  



IMHO.


Best wishes