I can't help with a recommendation but I will offer one word of caution.
I worked in a machine shop so when the plastic knobs broke I made my own replacements. I took a round disk of aluminum, bored a hole in the center and tapped in from the side for a set screw. Then drilled and tapped the face for the free spinning aluminum handle/knob. Works great for cranking the blade up and down,,,,,,,,,,, except if I want a very precise depth.
You see there is no "locking" feature for depth of cut and my saw adjustment turns very freely. The same additional weight of the aluminum "knob" is enough for the height adjustment to "self rotate" to where the knob is at the 6 o'clock position. Usually this is not an issue and may not be an issue at all with a radial arm saw, but a "balanced" handle would be ideal.
Ya I know, I need to correct the handle I made by drilling a hole or two in the aluminum disk to offset the weight of the knob.