Wes: never seen a Nautilus 4 way neck machine, sounds logical. Seen a few regular neck machine in rehab centers before, but regular design. Most everything by Nautilus has superior function. Been told that most of the Nautilus equipment is sold to medical recovery, and some sport training centers, now days.
The wrestlers bridge is excellent, but perhaps not for everyone. Can hold a BB over head, for added resistance, when working the back of the neck. Wrestlers do a lot of manual resistance with neck exercises. Remembering that the neck can move from side to side , as well as up & down, they will apply pressure on the side of the head as the head is turned. Usually done with a training partner.
While a well made neck strap/harness is good and has built a lot of big necks, I prefer (personal view..do what you wish) manual resistance, using a long strap (judo/karate belts work very well also), applied by a training partner. The training partner can increase or reduce the effort of the exercise as the reps are preformed, keeping a consent pressure (almost like a Nautilus machine) on the neck muscles. And can work all four movements/functions of the neck it's self. Just place the strap on the forehead, back of the head, etc (might need a towel, as a cushion, between the strap and head). Can also tell the training partner how much pressure (increase or lessen) is needed, as you are doing the neck exercise.
This method of using a long strap can also work well with triceps training, you laying on a matt or bench as the partner applies resistance throughout the rep scheme. Good Luck.
Side Bar: Can also work in negatives with a strap/belt, where manual resistance is applied. Works extremely well when doing the triceps with a strap, also.