Welcome from NE Texas. I have made two tshirt quilts and quilted another someone else made. Lightweight fusible interfacing will help you with piecing and help you or your quilter with the quilting. The top will get pretty heavy quickly, so extra table space around your machine to support the weight helps. It's also a good idea to use a lightweight batting unless you really want a heavy quilt.
T-shirt quilts are a lot of fun to make and the owners LOVE them! Good luck and keep us updated on your progress.