Has anyone contacted these people? Alphaboard seems to be PERFECT for us and it is available in various dimensions.

http://www.biopacindia.com/products/category.asp?cat_id=4

If I am not mistaken, I had posted this link earlier and not received any responses.

VC

I contacted them. They don't entertain orders below Rs 5 lacks

VC thats is the exact foam board in the link you've provided that I was talkin about! its available in abundance here in Kuwait including 3,6,8mm flexible foam sheets.
The best materials for a complete fuselage airplane!
My guess! it has to be available at art shops, because when I enquired the stationary shop as, "what kind of people buy this" he quickly answered, "Artists"
because the foam boads are sturdy on the outside and soft on the inside, they tend to soak water colors easily.

Yes, this is common in stationary shops all over in Qatar too, and is the same material commonly referred to as biopac in India.

Here is a plane my brother cut out of this material :

http://www.rcindia.org/electric-planes/another-scratch-built-3d-foamy/

It is somewhat brittle, but very very affordable.  Commonly used for in-store sign boards and school art projects.

In kolkata, they call it the Sunboard, very sturdy.