I will be only happy to help in any way I can justuschickens59. Top marks for you for going out on a limb and making something happen in your area. I fully understand that allowing a flock owner on the premises of an egg production farm would not be allowed, it wouldn't be allowed here due to strict biological rules.
There are web sites that will give you plenty of advice about rehoming ex battery hens if you google just that. No need for the expense of special crates etc. We just use cardboard boxes of appropriate size, big enough to carry two/three birds, lined at the bottom with newspaper and straw. When you get them home you may find that have difficulty standing/walking, as they have never had the room to build up their muscles. Their feathers may be very poor and some may be quite bald. You may find that they have bald patches and bites on the back of their necks due to the competitive way they are fed.
They will need to be kept separate from the rest of the flock until they have gained some strength and mobility. You might just be able to section off some of your runs, and an area of the housing. Battery hen farmers in the UK have fed their hens on layers crumb and its something you would need to check. We found buying a small bag of layer's crumb and gradually mixing it with increasing amounts of layers pellets worked very well.
Keeping them indoors for the first few days, if you have a roomy shed would be a good idea if the weather is unpleasant. Having said that we acquired ours in February in the snow and they are housed in an ordinary hen house. They were still happy to poke their beaks outside and explore their run. You will be astonished at how quickly they will settle down. In the early days you may find them quiet and subdued, later as they try to establish a pecking order they will be bossy and noisy. Lots of feeding stations and water containers and a careful eye from any bullying will see them through this temporary stage.
I hope you can reassure the farmer that these birds soon settle down to a new way of life. Hen rescue has been carried out most successfully in the UK for many years and the full waiting lists of would be adopters bears testament to the successful integration of ex battery hens into the back yard flock.