I thought it was the other way around. That Wilhelm was offered the title of 'German Emperor' since he was going to be more 'first among equals' with the other various German kings and princes. I think it took alot of deliberating on Bismarck's part.
Sorry, but No!
The "first among equal" things organized by Bismarck would be 1871. Bismarck became Prime Minister of Prussia in 1862.
1848 the democratically elected parliament of the Paulskirche in Frankfurt offered a title for the Prussian King - thus Democrats chose their emperor then, and they wanted a "Kaiser der Deutschen", that is "Emperor of the Germans", their kings and princes weren't asked about it. 1871 they became an "Emperor of Germany" when their kings and princes could be convinced to do so thanks to the victory in France.
So 1848 would be a chance to get a democratically elected "emperor of the Germans". This is what this thread is about: not the militaristic, conservatice Germany united by Bismarck, but the more liberal - and maybe greater - Germany united by elected Members of Parliament in Frankfurt.
Austria IS allready heavily involved, since the German parts of Austria elected members of that parliament, too. And as the Habsburgs tried to suppress the revolution, they even executed some of those members of parliament. Thus, when the Hungarians could last longer in their revolution, and the Italians could be better, and the German Austrians were more successfull, too, and the rest of Germany would help their "revolutionary brethren" in Austria against the Habsburgs and the Russians, who helped them suppress the revolution, the revolution could end with a Germany that really stretches from the Baltic sea to the mediterranean, closely allied with an independent Hungary and a newly united Italy!