The difference between 80W and 100W is roughly 1db. That is at the point where most humans can not detect a volume change, and it doesn't matter to the ones that can notice. Even doubling to 160W is only 3db louder, which is "a bit" louder, but not by much. Twice the column takes roughly eight times the power, or 640wpc to get twice as loud as that 80w receiver. In other words, your requirement for a 100wpc receiver is nonsensical at best.
Chances are real good that you have never used more than 10wpc on your current receiver, and probably never even over 2w.