I would go with the Pfaff 130 for what you describe. When I bought a Pfaff 30, I kept trying to google information about it and would come up with info on the 130 instead. At that time there was a blog for a man who dealt in the 130 and was well known for his advice. I have seen advertisements for the 130 indicating it was good for use in a shoe repair shop. To me the Pfaff 30 is not much different than the Singer 185J, and I thought the 130 was just a bit more souped-up. Some of those old Kenmore sewing machines are very powerful.
I am thinking that I have seen something on here about "quiltedsunshine" working in a sewing machine repair shop, seems that would qualify her as knowledgeable regarding powerful machines.