Yamaha DTXpress/DTXplorer/DTXtreme

Hello -

I just read that last post about how the DTXpress doesn't allow you 
to load samples or any sounds into it.  I REALLY need something to 
add to my setup that is like the DTXpress:  size, mountability, 
outputs for triggers, many good effects on it, MIDI, etc.  A 
start/stop input would be great too...  
BUT, I also need somthing that will store sounds that I create.  

I have NO idea where to begin to look for something like that, or 
what some good ones are, etc.  Anyone have any suggestions on where I 
can start to look for this?  Or a suggestion on a good unit?

thanks!
eddie