They're all basically universal with the likely requirement for custom mounting.
You've cut up the frame so any turn signals will need custom mounts. Otherwise just about anything should work. Will likely need an LED compatible flasher relay if you go that route.
Ditto for tail light. You'll want running and brake lights. As long as it's 12V you shouldn't have any trouble.
Handlebars are 7/8" OD tube. Just about anything 7/8" should work as long as the stock mounts fit within the middle width of the bars, or whatever you want if you do custom mounts.
Haven't bought a fender yet but you can match up wheel diameters. Any non-stock fenders will need some customizing to mount.
