Hello BA,
when my old drummer was using the 2box set, he moved very quickly from the original Hihat pedal to a pearl pedal. No matter what brand you use, they all work with the 2box-Hihat-cymbal!
The only important thing IMO is, that you have to get a pedal, where you can set the spring tension, which is not possible with the original 2box pedal, which moves much too easy with it's weak return spring.
Unfortunately I sold the whole kit (just kept the 2box module for me) so I had to get another Hihat brand when we got back using trigger drums in my rehearsal room, cause there is still not even one crappy 2box-cymbal available (that's something I still find extremely fu**ed, cause IMO the 2box cymbals really did a great job.