Need ballast switch

[gregzz4]

I'm no electrician, but if it's 4-wire, I'd stick with it
A 2-wire usually just interrupts the hot circuit
In your case, they've probably got it wired so it interrupts both the hot and neutral circuits

And for 150w, even with the draw when the ballast first fires up, you'd be fine with a switch that can handle 5amps (3amp min as your light runs on 1.25A)

Good luck in your search