There is no harness available to run dual displays AND dual mobile processors. That I am sure of. As Ole mentioned, you'll have to have your dealer send both of them in and get you a card with Autotrac AND Harvest Doc on it.

After that I don't see much point in running dual displays. My uncle hasn't been doing any mapping but he's not going to get a choice this year as all of it will be mapped. Other than stubbornness and impatience there's no reason we haven't mapped everything for the last 3 years. My 76 year old uncle could figure it out the season he ran the combine so dad sure as heck should be able to.