I made my portable observatory panels 88" tall. I am 6'5" and love the added height. Having the panels taller than the scope also negated the need to flock. Contrast went way up. I love using mine. Here is a link detailing their creation.

http://www.cloudynights.com/ubbthreads/showflat.php?Cat=0&Board=telescopes&Number=3035307&fpart=&PHPSESSID=