Armosmithing need some lead!Follow

Ive been looking for quite a while with a friend of mine and i must say im quite puzzled this is about the quest (the art of the armorsmith) in wish u need Ornate mythril helm X4,Ornate mythril boots X2, and one ornate mythril breastplate. Where are those pattern can they be bough? must they be quested? Any lead would be appreciated