Custom Tshirt Design

We are a fine art gallery and boutique gift shop. We sell apparel from Simply Southern and it is very popular. I am a fine art photographer with a strong following in the area. We are looking for graphic designers to provide tshirt designs along the same look and feel as the Simply Southern brand but incorporating the local area and my landscape photography into them. This would be a full design process between me and the chosen designer. Looking to pay per accepted design if possible. I have attached a sample of a Simply Southern design, as well as one of my landscape prints for reference.