Yamaha DTXpress/DTXplorer/DTXtreme

Hello 

I am thinking of upgrading my DTXpress module, I have 4 other pads 
that I would like to kook-up. Is it possible for me to used th Alesis 
DM5 or DM Pro with the original Yamaha kit?, or should I just only 
look for a Yamaha product?

Thanks

Daniel