It seems that the hub is actually 130mm O.L.D., so with a spacer (there are specific such spacers for this problem) and if I dish the wheel according to this I should be fine.
The reason why I'm going for the 3-speed is that I will add an electric (Bafang) mid-drive engine to the build, and the 3-speeds have a great reputation for handling that power. With an engine I hope the 3-speed will be enough.
/Magnus