Haha man, this is basically my story as well. Going to have a baby in a couple months and my accord coupe won't work too well. Thought I was definitely going 2016 Accord, and then they unveiled the new civic.
So there hasn't been any info yet on the Si, some speculate that its getting a detuned 2.0t from the type R. I'm hoping they add an auto as an option. Info on the Si should be here within the next few months.
As far as the differences, the Touring is basically all the options, leather, premium sound, honda sensing, navi, led headlights etc. It will have the 174hp 1.5L turbo with a cvt trans.
The Si will have more power and be more geared towards the enthusiast with suspension tweaks. However it most likely will not have leather, navi, sensing standard.
IMO I'm waiting to see if the Si has an auto trans, if not I will be looking more at the Touring.