Digital BW, The Print

I have been reading documentation from Paul Roark site about BO
printing.  According to what I thought I read, I could do this using
my Epson R1800 using just one black cart with Eboni inks.  When I went
to the MIS site, it got very confusing, so I used their little
Customer helper module to ask then exactly what I needed.  I got a
reply back from some guy who said I should research the site for my
answer. What?  So I emailed them again, and got a response back today
saying I can't do a BW print using existing carts.  I had to buy three
carts from them, containing various black inks, but I couldn't do it
with just one cart.

Is this true?  I can't exchange my OEM black with Eboni ink?  As you
can tell, I'm quite the newbie and am a little timid about jumping in
deep waters.  

Uncle Dannie