I have grown wheat in my gardens for a few years. Banatka is a heritage wheat, but it is modern wheat and would not be good for people with celiac disease. The ancient wheat Einkorn is the one that has different proteins from modern wheat and may not cause problems for people with celiac disease.
I grow Alice white clover as a companion crop with my wheat. Hairy vetch does not do good things for small grains. It tends to vine up onto the straw and pull the wheat down. Also, once it goes to seed it is VERY hard to get rid of. Vetch has "hard" seed, which means some of it doesn't germinate until year 2 and some not until year 3. To get rid of it you have to rogue out the vetch completely for at least three years. Ouch.