Pieced together from many items, including the cheap-o cowboy shoulder support (25$), a flash bracket (10$), Long lens support (~60$), and some kinda handled quick release thingy (25$)
Features both a quick release plate on the lens support, and one on the "handled thing".
thanks! Haven't had to use it practically yet, but will post some feedback once I do. I really like the 'handled thingy', I'm going to try to find it listed somewhere.
HEre is the the flash bracket support that I was using almost exclusively before I added the other pieces: