I think all dementia a are lumped together, though there may be something for those with early onset. Many have mixed dementia, usually Alzheimer's and vascular, these being the two most common. You will find that even those with only one type will develop in different ways anyway.
What kind of services were you thinking of? There are various things like coffee clubs, singing sessions, chair exercise sessions. Or would he go to daycare? Get in touch with Alzheimer's Society, or Age uk or your county family Carers and will acquaint you with things that are available in you area.
I see you are working with people with dementia, you can start you own activities to suit the people with whom you are working!