You can figure out how long the one on Larry's is as it goes from the point of the front window to just above the rear clearance light. I think his is a Catalina model.
Here are some links to different types of case awnings that could work. They're quite expensive so I hunted around on Craigslist for a long time to find a good used one for my Brougham. The easiest way to mount it will be to install an awning rail on the roof. The awning will then slide into that and you typically have to bolt the housing to the body to keep it from flying off.
Carefree Freedom Patio Awning - http://www.carefreeofcolorado.com/caref ... egoryid=45
Dometic Horizon II Case Awning (this is the same as the Fiamma I have on my Brougham) - http://www.dometic.com/enus/Americas/US ... taid=72979
Catalina Case Awning - http://www.dometic.com/enus/Americas/US ... taid=70423
