Welcome, if you have not found a tonneau yet check out 1-880-craftec or go to their website, they have a nice inexpensive tonneau cover. Only change I would make would be to install clear plastic along the edge of the bed and the tail gate.....to keep from burning the paint.....Kieth
Here are pictures.......just click on the right side arrow to scroll thru pictures of tonneau install, cost about $325.00
http://kieth.smugmug.com/Trucks/66-GMC/i-hSj33GX/A