Three lives were written about St. Simeon by his contemporaries. They have been translated into English and published in one volume by Cistercian Publications, in Kalamazoo, Michigan. The translator is Robert Doran. The ISBN # is 087907 412 4 (hardcover) and 087907 512 7 (softcover.) The name of the book is The Lives of St. Simeon. I can't recall where I got my copy. Light and Life may have it, or probably Amazon.com.
I love St. Simeon. I often ask his intercession and there have been times when I could really feel that he was praying for me.