Fixing the roof

This is probably going to be a saga. I need a roof refurbishment of a ground floor "outrigger" kitchen, see the photo below. In the past I would have done this myself, but ill-health and retirement means I'm not going to be repairing slates myself.

Step one is asking for quotes...hence the photo on here. For more on slate see River Dee Geology - although it is likely that "modern" slate is Chinese.