@drysailor: Think the roll cage/structural reinforcement might be required if you will be carrying passengers. That's what I read on a site yesterday.
@ArtW: Well, the fact that they haven't provided an AutoCheck report that I asked for over the weekend pretty much kills any idea of doing business with them.
Well, I finally found a place with hightop/hi-top pricing.
http://www.discountvantruck.com/vantopsraisedroofs/vantops.htm. Note that the prices are just for the top itself and do not include delivery or installation.