Wrestler have big necks. When you wrestle, you use your neck meat to move your head around, and also to keep your opponent from moving your head around.
So for the best neck, I would do static/ supportive/isometric stuff like bridges and having your homeboy push your head while you resists. Then do dynamic/ moving stuff, like headstrap work. In addition to working your traps, of course.
For the wrestler's bridge, find some kind of Matt or something. Start on your knees face down, and the top of your head, with your hands down for support. Roll your head around, and get a feel for using your neck muscles. Get comfortable. Then, work on raising your hands. Take your time. Once you're OK with that, get up on your toes and head, again using your hands for extra support. Roll your neck/head around. Get comfortable. After awhile, lift your hands up, so you are on your head and feet.
You can use bands in pretty much the same way you would use a headstrap. The bands are way easier, and you can even go side to side, which is a nightmare with the harness or plates balanced on your head.
When your neck and back get more stronger/coordinated/flexible together, you can flip over, and start to bridge belly up.