I can tell you that going from 100wpc to a 250wpc higher current design with my 88db speakers in a 14 x 24 room has turned out to be an improvement, but this was mostly due to the higher quality of the bigger amp.
I would go with a minimum of 100wpc and buy the amp with the best sound that you can afford.
I would go with a minimum of 100wpc and buy the amp with the best sound that you can afford.