for vendors look at Homegrown Audio, Chris VH, and maybe the Vampire cable websites. I believe these all sell wire you could use to DIY XLR IC's. There are also a number of vendors who sell DIY type cables already pre made. In particular the Element Cable has good designs using Belden wire, and was recently favorably reviewed. A list of vendors can be found within the following links.
http://www.audioasylum.com/audio/cables/messages/96214.html
http://www.audioasylum.com/audio/cables/messages/93177.html
http://www.audioasylum.com/audio/cables/messages/96214.html
http://www.audioasylum.com/audio/cables/messages/93177.html