Hello Kurt ,
2nd Panzer fought in the Balkans in 1941 , before driving down into Greece . Have you looked for any original images of this Division ( Vienna Division ) at the time of the Balkans invasion ? If not , I imagine they would have worn what they did during the Polish and French campaigns , ie standard wool uniforms . What helmets/equipment they had is hard to say , there was so much so called obsolete kit about at this time .
Regarding the Tropical uniforms. DAK used the official tropical uniform , with tropical insignia and NCO rank tresse. It is , I think, highly unlikely that this was issued to the 2nd Panzer for the invasion of the Balkans ( 2nd Panzer went to Romania ) .
Regarding your question about DAK/Tropical; DAK used tropical as I mentioned earlier , there was no separate DAK uniform , just a DAK cuff band and regulation tropical insignia, pith helmet etc.
Hope this is of some help ,
Jäger Stefan Halle 3./I./Geb.Jag.Reg.100