I highly recommend Robin Lambdin http://www.vintagestylestainedglass.blogspot.com/. She made a transom window and glass door insert for me for a very reasonable price. I designed the pieces and she did an outstanding job buidling them. She’s also happy to make one of her own designs for you. She’s super flexible and easy to work with. Her husband does installations, when desired. She’s up in Baltimore, but has done plenty of work for DC clients and is down here in DC pretty regularly.