T206s are right around .013 thick. The weight it's called will depend on the type of stock. The coated stuff mentioned earlier sounds about right. I'm not sure what category it fits into.
There's some good info here
http://www.businesscards.org/design-...g/paper-guide/
Comparing stock, it's very similar to the acid free comic backing boards, which are a bit thicker.
If the printer is still clueless you could try the place I worked for. Not cheap, but good quality.
http://www.arlingtonlithograph.biz/
Steve B