If you can get a fly sheet that will work with the neck cover, then I would definitely go with that. Just leave it on him 24/7. If he's hard on fly sheets, look for one that's labeled as "protective." They usually have more durable mesh.
If you have a Tractor Supply or other farm store nearby, I'd definitely get some of those ear tags though. Once you get your fly sheet, you can sewn or tie them on to the neck cover too
Here are the ones that TSC carries: Tractor Supply Company - Insecticide Ear Tags