FWIW I think you did the right thing getting the 59. The head tube on the 56 is really very short and you are already using 25mm spacers with a flipped up stem. for the 56 to work you need 30mm spacers under a 120mm stem and you will still end up slightly lower at the front than your existing bike. reach is really the issue here and in my experience its nicer riding with less spacers and a shorter stem then it is riding with loads of spacers.

Anyway let us know how you get on.