Architectural Model Supplies

or any kind of architectural supply store ....

Thailand is more suitable and less expensive.

http://www.bangkokcompanies.com/categori ...

The best in my opinion, is a small store near marker Maharaj Pier (between Ta Ta Chang Pier and Pier Prachan / Thammasat University). I'm not sure of the name of the street ... could be either Maharaj Rd or Rd Prachan

This place is near Silpakorn University, one of the best schools of architecture. Thus, the store offers everything you need.