Yamaha DTXpress/DTXplorer/DTXtreme

i have had my dtxpress for awhile, but i only bought the module which 
i got off of ebay.  For pads i used the logistix plans and they work 
pretty well.  however, i've been going without a hi-hat controller 
because i haven't been able to get the dtxpress pedal by itself and i 
was told that the pintech pedal is not compatible.  I think i heard 
somewhere that it might just be that the polarity for the dtxpress is 
different, but i'm not quite sure.  i figure that if it is different 
from pintech it won't work with most other pedals.  I think it might 
be possible to obtain the dtxpress pedal through special ordering, 
but i've heard a few negative things about it, so i'd rather try 
another brand if possible.  Does anyone know 
where i can get a pedal that's compatible, what kind to get, and/or 
how to modify one so it will work with the dtxpress?