Source for rectangular RV Air Conditioner ducting?

[RedneckExpress]

Hey all, I'm having a bit of trouble locating a source for the narrow rectangular aluminum ducting that is used (usually in the ceilings for A/C units) in RV HVAC systems. 

I'm in the process of restoring a 40 year old RV, and am adding a roof A/C unit.  The used A/C unit I ended up obtaining is designed for ducted use (though it can be run with a straight down discharge),  and since I already plan to take down the interior ceiling, and figured it would be a good time to route a duct line over into the nearby cabinets so I can add A/C ducting around the unit instead of just freezing us out in the dinette .

Thanks!

[DaveVA78Chieftain]

http://www.insul.net/prod_ultrasduct.php

[Rickf1985]

And here I was getting ready to say you would probably have to find a local tin knocker to build it for you. I swear there is NOTHING Dave cannot find!!! N:(

[JerryP]

Any local sheet metal shop can make exactly what you need.
Just drop in and ask them, they may ask for a rough sketch, and the measurements you want.