The First Boer War took place in 1881, so he would not have taken part in that, especially if he appears in 1881 census. As we were defeated by the Boers, the 2nd Boer War (1899 to 1902) is usually known as the ‘Boer War’.
Cavalry and infantry regiments were completely separate. But a saddler’s skills would be needed in an infantry regiment to look after the ‘webbing’ which was leather in those days, as well as any requirements for an officer’s horse.
You could try a post on
www.britishmedalforum.com requesting a lookup on the medal roll for the North Staffs Regiment. A member may have a copy. You should put the regiment in the title. Otherwise it will require a researcher to visit Kew to look for his papers.
Ken