Shell books with the desired characteristics are inherently very
expensive, and only a few can afford them.
 
There is an alternative for books of good quality and adequate
information:  The CD.  CD's can be produced at quite low cost (though
not at reduced work on the part of the author).  One major problem is
that most people prefer reading a physical book.  You can print the part
of a CD book that most interests you at a specific time.  If the
graphics are available easily (often not the case), you can print them
separately and lay them out on your table for comparison of all the
species you would like to compare.  This flexibility is not available in
a physical book.
 
Why not go CD if you have the time, material and ability to produce a
book?  You probably can't expect to make much money by writing a shell
book on an obscure family in any event.  Do it for the overall good of
malacology.  In the process, you will be awarded with the gratitude of
people who are interested in the family, if the CD is really worth
while.
 
Many old books had illustrations in a separate section.  This allows
looking at the illustrations while reading any page of the text, and
still permits economies of printing color in one section.  Compared to
having the color section as part of the text book, it is a great idea.
This also brings up the possibility of having an excellent black and
white text book with a CD holding the graphics.
 
Aloha,
 
Wes