Loft
the wainscot is clear Pine; the old-fashioned stuff. You can purchase it from most full-service lumber yards. There is also a great wainscot product made from MDF (medium density fiberboard) that looks great painted. I'm working on an attic project right now http://www.homerestorationinc.com/portfolio.php?idx=5&subidx=6 using that product (see attached photo). The doors are made from Poplar with 1/4" MDF panels.
built in bench and lighting above and window
dormer (windows only) with built ins under the eaves rather than drywalling the whole dormer down to the floor.
Q