Here's a quick and dirty roll up top. Could be used to either open the top or use it over the clear with a black tarp for black out?
http://http://www.youtube.com/watch?v=sj0bTU5Fs2o
Your link doesn't work for me.
But since I'm here, this is a link to a motor designed to drive window shades. This should work well for a smaller system.
http://www.laaudiofile.com/addamotor.html