Yamaha DTXpress/DTXplorer/DTXtreme

Hi,

I'm interested in buying a Yamaha DTXPRESS III kit and so far know 
very little about it.  To provide a bit of background, I've been 
playing drums off and on (mostly off lately) for over forty years, 
and decided I'd like to get back to it using an electronic kit (I 
still have my original Ludwig set from the early 1970's, but it's way 
too loud to play in my townhouse).

I checked out the Yamaha kit at the Guitar Center near my home 
(Towson, MD) and it looks perfect for my purposes.  

The three questions I have at this point are:

1. What's a good price on the DTXPRESS III?  Guitar Center is 
offering it for $1k, which includes a Yamaha single-stroke bass petal 
along with the standard kit.

2. What amp and monitor speakers do you recommend for use with the 
kit?  Guitar Center has a floor display Roland set (can't recall the 
model number, unfortunately) they are willing to sell me for $500 
(originally $695).

3. What venues exist online for selling a used acoustic kit (full set 
of Ludwigs with Zildjians)

Thanks very much for any help you can offer.  I haven't played for 
over 15 years now, mainly due to noise considerations, so I'm really 
excited about this kit and getting back into percussion.  It's an 
entirely new world since the last time I shopped around for drums!

Best regards,
Dan