I would just search the arcade section of ebay for joystick.
The Midway ones come up regularly.
If you are looking for a good 8-way, keep an eye out for Discs of Tron sticks, or Xenophobe sticks.
They both use the same trigger system as the Tron sticks, but the handles lean forward to make it easier to use the thumb buttons.
The Xenophobe ones will usually go cheaper than the DOT ones because the handles are black.
Most of the time you will just see them listed as "arcade joystick", or something similar.
If you want the stick for Tron, nothing but a Tron stick will do.
They are a 4-way stick that is just sloppy enough to allow you to hit diagonals.
That prevents you from zig-zagging in the light cycle stages, like you will with a true 8-way.
I wouldn't waste the money for a new Happ stick.
They are functionally the same stick as the Xenophobe sticks, but you are going to pay alot more for them.
The original Midway sticks are very sturdy.
The weak spot in their design was that the handles were prone to breakage if you pulled on them too hard.
As a picky point on your grammar, NOS means NEW Old Stock.
You can't have used NOS because it wouldn't be new.
There are alot of people on ebay who use NOS to attract people to obviously used items though, so be careful.