The bench seat was standard on the Yukon Denali but am not sure about the XL. Anyway, the bench was longer on the driver side...I guess that's the 60/40. You could do a swap, but I'm pretty sure you'd have to drill holes for the center seat bracket. Also, for a good match the seats should come from a Denali as the standard Tahoe and Yukon had different leather patterns.
As for adding a center console, a center console from a 2000-2002 Tahoe or Yukon might work. Here's one on ebay that is kind of what I'm talking about
:
http://cgi.ebay.com/ebaymotors/02-Ch...spagenameZWDVW
These were two-piece units and the one in this link is missing the front extension piece that goes up against the dashboard. Thus the hole in the front.
Some were made without the second piece and didn't have the hole in the front. That's what you'd look for if that makes any sense. The consoles for 2003+ were one piece and wouldn't work.
You'd still have to drill holes to mount the console though and I have no idea if it would fit but seems like it would. You might try posting this on the Chevrolet Tahoe forum as there may be a little more traffic.
Hope this helps.