I had the same issue with my thoroughbred. If he knew his buddy was there but not in sight it was utter chaos. It came to the point where this solid 16.3hh gelding would drag me and pull me around to get to his "girlfriend". Simpley put, we serparated them.
We turned them out in different paddocks but allowed them to be near eachother in the barn. We started taking him out by himself and "tying him" when he got hyped up and uncontrollable. We used a rope halter (you get it where natural horsemanship items are available) with knotted pressure points. We would tie him to a post and just let him wear himself out until he got the point. After he calmed down we would bring him back to the barn and leave it for the day.
Within about 2 months you wouldve never guessed he was buddy sour. If my method is not usuable perhaps try watching some natural horsemanship videos, I know they work wonders with outs.
Ps Sonny love your idea!