Digital BW, The Print

Hi all, 

I've entered in digital world recently, and I'm shooting with the 
Olympus E-1. 

I print color with the EPSON R800, but BW printing is not good enough 
for me (there is metamerism). I don´t know if there is any software 
(imageprint...) for the R800 which works well, or if it´s worth 
buying a new printer for BW, with four gray cartdriges 
(piezography,...). 

I apologise for my poor english. Thank you !!