Stramit panels were unfortunatly, only made on this side of the pond, very briefly.
The production facility was in Texas, the shutdown seemed to have as much or more to do with the market structure here as opposed to Western Europe and their desire follow the precedent of their home marketing strategy of multiple production facilities near major population centers with a very limited shipping radius, than an inability to create a market here or the patience to allow one to develop.
http://www.stramit-int.com/panels.htm I havn't heard of anyone expierimenting with self made SIP's in years, though I can see why someone in the hinterlands would consider it. I would guess this has more to do with ready availibility and the insurance of some manufactures warranty represents than anything else