Take a look at the Trekking handlebars too. They'd be easy to adapt on. Fenders, rack, lights, a pannier bag of some sort and you're good to go. On rough streets, you want to keep the bigger tires. Look around and see if there's a bike project shop with second hand parts like fenders and racks, along with workstations you can use. Check the army surplus stores as you might find bags you can easily (and cheaply) adapt as panniers. You've got a good, very useable bike that should keep you going for years.