Disklavier

Hello!

I am new to the group and am working to acquire a Disklavier, but can't afford $30K for a new DC1A. 

Two questions (sorry if these have been answered many times before):

1)  Any good source or bulletin board to find a quality used instrument?  I would prefer any model 5'3" (black), but would enjoy an upright as well. I am already watching eBay regularly. 

2)  If I can find a good used Mark II, can it be upgraded to Mark III functionality?  Any ideas about cost?  Is this a bad idea?

Thanks.

Barry