First of all I would read up on a disease called Blackhead. Chickens are more resistant but it is a killer and there is no cure for turkeys. The ground is infected so best to keep them apart ,dont even put turkeys on ground that has had chooks on, it is easy to say 'I have had no problems ' until you know someone who has lost two flocks through infected ground. They will get on but occassionally do scrap with chickens when they meet in a cocky mood and it is not nice as they dont give in My turkeys roost at chest height in a stable and I have no problems getting them in as I only feed them at night. They graze like a goose so need plenty of space , a small paddock is ideal not a chook run . mine share with the goats.They can fly depending on breed so they will have to be clipped if they do.
So basically best kept apart, turkeys in a paddock with plenty of grass and a large shed and chooks in their run/ seperate paddock with their nest boxes quiet for them. Good luck.Turkeys are great fun.