Yamaha DTXpress/DTXplorer/DTXtreme

I am looking at buying one of these sets and would like to know if 
dual or double triggered pads can be used (mainly for rim shots on 
the snare and for a ride on the cymbal)? Is it possible to do cymbal 
chokes? Also can you get a brush style off the snare settings? I have 
a lot of questions and really no one to help me at the store.  Any 
advise or comments would greatly be appreciated.  I'm new to drumming 
and want to get the best bang for the buck.