I have 4 lovely birds who entertain me and the kids no end. One word of caution is be careful adding new birds to the flock as your existing ones wont like it and will beat up the new ones especially if they are smaller.
I added a beuatiful french skyline (called Nicole) to my existing three and they had a field day bullying her. She even had her own coop inside the run for the night time but they still sat on her and pecked her head feathers out during the day.
It took a good couple of weeks before they stopped picking on her so if you have a spare coop put the new ones in there and make it so the others can see them but not get them and they will soon become friends.
You will find its the lowest of the "pecking order" in your existing flock who will be most aggressive to try to climb the ladder as such with the others.
In my case Nicole grew very quickly and soon overtook Marge who was bullying her and one day turned round when being chased and stuck the nut on her. It soon stopped.
Another good tip I got was put the head hen or most placid in the coop with the new ones on a night and she will put her scent all over them whilst cuddling up and your more flighty existing ones will get confused by this and accept them even quicker
I love my birds especially when I'm out pottering in the garden and I turn round to find them all aleep in the veg patch on their backs getting some sun on their bellies.
The complete runner is one of the best shops in the North. Run by husband and wife for years both runners in the younger days.
Dont think they have a treadmill but to be honest they dont need one. Take a pair of oldish shoes/trainers and they will get you walking across the shop, up and down a few stairs and know exactly what you need.
They are on the road from Otley to Ilkley A65 I think before you get to Ilkley
up and running in centre of leeds do gait analysis on treadmill if you really desire it too.