Ok pompkyn, have I got some news for you. I found the site where I downloaded Wrights Meyer-May house. Here's the link.
http://thesimmersclub.net/downloads.html
And while I was searching for it, I found that this site had a number of Wright's houses and a lot of craftsman style houses.
http://www.elitesimbuilders.com/
And one more: Neptune Suzy has done a rendition of Falling Water located here:
http://ts2creations.com/index.htm
Finally, google Sims 2 Frank Lloyd Wright and you will find some other hits, mostly on MTS2