>>14805994U. Bars wise, no I didn't cut them. My last 2 bikes were a flat MTB bar 1x9 frankenbike thing for a decade+ and a newish drop bar; so I opted for something swept back and wide. FSA Metropolis.
Fair enough on tires. This size is what I have on that drop bar bike and I love it. Not slow, similar handling, and big enough to add some comfort and off pavement ability. A super wide tire single speed sounds like a cushy slow roller.
Honestly, as much as I love disc brakes, rim are just fine. I went Deore V on this and they're solid. The only real downside to rim brakes is needing to keep your wheel true more closely in line.