I had a dicken’s of a time trying to come up with a good way to customize the Hylafax coverpage for our company. I was able to get partially there from modifying some postscript. But the comments section kept throwing me for a loop. Then I finally found this link while browsing an ftp site:
ftp://ftp.sgi.com/sgi/fax/contrib/covers/jf-mycover.ps

I was then able to use TGIF and plunk our logo and confidentiality notice in there. It does take some tweaking.