Digital BW, The Print

I like printing "Black Only" with my Epson 2200, but I think Epson's 
OEM "matte black" ink looks too brown.  So after some research I 
found out about the MIS Eboni black, and tried to order a cartridge.  
But MIS tells me it's only available for the "light black" position.  
What?  I don't want to use a whole new workflow, in fact I want to 
leave all the Epson color inks in there and use the standard driver.  
Am I missing something?  Isn't there a way to just swap out the black 
cartridge for an Eboni one?

Thanks.