Hi Kate,
I don't know of any site for Heaton Norris, perhaps someone else will be able to suggest something.
I noticed on the Stockport historical site an entry for 1872, William Banks, Chemist, 72 Lancashire Hill, have you seen it? I seem to remember that someone wrote a book about Heaton Norris and that there were photographs in the book but right now both title and author are refusing to come to mind.
Regards,
Pat.