I offer Sunday starts as a custom option. Please submit a custom order request for a quote. If there is enough interest in a Sunday start, I will do my best to offer it in the shop. I hope to incorporate Sunday start inserts in my shop eventually!
Interestingly, there is quite a bit of history on the Monday vs. Sunday start. The International Organization for Standardization 8601 states Monday is the beginning of the trade and business week. However, culturally and historically, Sunday has been the beginning of the week as it signifies a day of rest (Sabbath).