Maresli, have you been researching your Bohemian ancestors long? You've mentioned the Třeboň archives (a miracle resource!) and the Highholder site, and I've found some other cool resources as well. You've probably run across them, but for others who haven't:
Zaniklé obce a objekty po roce 1945 (Roughly: "[Bohemian] towns disappeared since 1945")
Czech-language version: http://www.zanikleobce.cz/
German-language version: http://www.zanikleobce.cz/index.php?lang=d
Or you can toggle between languages by clicking on the flag at the top right of the page.
German-Bohemian Heritage Society, New Ulmhttp://www.rootsweb.ancestry.com/~gbhs/
I've bought a few books from there, the best is "German Bohemians: The Quiet Immigrants," which describes a lot about their lives in Bohemia and here in America. Bought one of their cookbooks too.
My Bohemian family migrated to St. Paul's Frogtown neighborhood too, with some landing in Oshkosh, so we're looking at the same immigration stories. What are other good Bohemian resources you know about?