A modern-day Weimar would be perfect, IMHO.....a little wankage might not hurt, either. 
Wendish? Never heard...?
<_< but those areas are actually German and haven't been Polish/Czech for ages.A Germany without any Polish and Czech Provinces(A Germany without Lebus/Lubusz and Lusatia).
<_< but those areas are actually German and haven't been Polish/Czech for ages.
Habsburg Constitutional Federal Monarchy with OTL German borders+Austria, South Tyrol, Carniola, Istria, Trieste, Alsace-Lorraine, Luxembourg and Lichtenstein.
A German Republic as in OTL is the best option, I believe. But Germany should get back "German" lands taken away by force after the defeat in the WWII. An option for Nazi Germany also should have been included, at least to know if anybody would vote for it!