The good news is the 12 and 16 row stuff is readily rebuild able.   I bought a 16/31 Kinze a couple years ago for beans that was used hard and put away wet.  Bunch of shop time during the winter and a pile of boxes from Shoup it’s a good machine.   I’m confident as long as a person runs a Deere or Kinze aftermarket parts will be readily available.   Problem for me is my planter tractor is at 110% to pull it yes I saved a pile of money buying an odd size but really could use a different tractor to pull it.  

We’ve ran separate planter for corn and beans and it’s worked great for us.  Plenty of times both have been running at the same time.