How could you get Austria included in the Germany Empire upon the German unification (doesn't necessarily HAVE to be at the same time that Germany unifies, could be after)? The main problems I can think of is the Habsburg-Hohenzollern rivalry and the recent Austro-Prussian War.
The POD can be anytime before 1900 and the unification of Germany can be anytime. I just mainly want to know whether Habsburgs or Hohenzollerns or someone else will sit on the throne (and whether that throne sits in Berlin, Vienna, or another city), what happens to the Prussian Empire and Austrian Empire outside the borders of Germany, and how all this will alter late 1800's/early 1900's Europe, eg is a European War butterflied away or is it still inevitable? What alliances will form now that there is no German-Austrian War? Will Germany take a similar position on its colonies or will they be more "Germanified" (if you get what I mean)?