Digital BW, The Print

I am trying to get the best out of my Epson 2200 and am thinking about 
delving into the realms of quad tone printing and have read a lot of interesting 
things in this forum about the various options available (Epson Pro RIP vs 
Imageprint  vs quad tone RIPs like Roy Harrington's QuadTone RIP).  But 
before I go too much further I have a relatively simple question:

Are quad (or sep) tone ink cartridges available for the 2100/2200 and if so 
from where or does one have to hack and refill the Epson cartidges?