Yamaha DTXpress/DTXplorer/DTXtreme

Hi all ive just bought dtxpressII and i must say im totally 
satisfied with it. I have some stupid questions though.
first what is this little thing.
" 
YAMAHA - BP-80
Yamaha BP-80 Bar Pad, stereo, two zones
" 
I was reading about it in the manual but couldnt find out what it 
was.

2nd question. Is it possible to connect a ordinary pc and send and 
recieve midi files through "to host" to a com-port. or is it worth 
it to buy a good sound card to the pc, and connect midi in /midi out?

and what preset drumkit do you guys sounds best?

regards

Leffelejon