I can't remember where I read this, but I think there was a plan of Napoleon's to set Prince Esterhazy up as a sort of puppet king in Hungary. However, the prince wasn't too impressed with the idea.
Yes, he offered Esterhazy Hungary (which was basically half of the Austrian Empire) which would have crippled the Habsburgs. Esterhazy didn't take the bait and was loyal to HIS Emperor. Napoleon later congratulate himself on his leniency to the Austrians as if this offer never happened.
In addition Napoleon did dismember Austria to a large degree by 1815. They had lost Croatia, Slovenia, Dalmatia, the Tyrol, parts of Poland, the Austrian Netherlands (Belgium), their ancestral lands in Germany proper. It's no wonder they never would give the fight.
Outside of one of his mediocre siblings I can't think of any monarch Napoleon could have replaced the Habsburgs with that wouldn't have eventually turned on him. One of the French marshal perhaps but that would have been an insult too far for the citizens of of A-H.