Hi Cath,
Took me a while, but if I'm right, John and Susanna were Nonconformists and had their children baptised at the Congregationalist Church, Colegate, Norwich
John died in 1815, and I think his will is on the Norfolk Sources website.
I couldn't do a direct link to the image, but if you click on Probate, then type in John Coleman in the search box, several pages come up.
Your John's is the one dated 1816 - and is on two separate pages - page 1 and page 4
http://www.norfolksources.norfolk.gov.uk/DserveNS/Yorkslass