The
Internet Archive Wayback Machine can be very useful for unearthing lost info relating to Cakewalk and
rgcaudio :
http://web.archive.org/web/20071011015934/http://www.rgcaudio.com
For instance, the sfz format spec, version 1.0 :
http://web.archive.org/web/20071011041531/http://rgcaudio.com/sfzformat.htm
and a directory of some sfz sample files :
http://web.archive.org/web/20071020025349/http://www.rgcaudio.com/sfzsamples
The forum software won't preserve a link with an http address contained within it, so you'll have to copy the above links (the whole line in the box) and paste into your browser's address field, or highlight the line and open it as a link.