I have a project of taking photos of headstones in Canyon County, Idaho and happened across your research on the message board on Ancestry.com. I have the following listings for the Ball surname in Kohlerlawn Cemetery in Nampa, Canyon County, Idaho. I see the A L Ball is probably your Amza or Amasa Ball and Sophia Rachel Ball, his wife is there also. These photos are free upon your request.
Ball, A L 1827-1911 KL
Ball, Landon C 1860-1937 KL
Ball, Sophia Rachel 1840-1922 KL
Ball, Susana C Fahrney 1858-1928 KL
Also you may want to search the site further for other connected relatives as there are other Ball family members buried locally that may or may not be related. All photos are free and there is a small search engine for the website there. Enter the surname you may want and good luck! Simply go to my website athttp://freepages.genealogy.rootsweb.com/~holton/cempics/head...