Digital BW, The Print

I would like to achieve printing neutral B/W prints using the Epson 2100 and 
Archival Matt Paper. Firstly, should I print from a grayscale file or an RGB file 
that is either desaturated or made B/W by using the channel mixer in 
Photoshop? Secondly, does the 2100 have to be linearized using the Gray 
Balancer in order to correct the colour cast that I seem to get? The results I 
have had using just black ink are not good either.

Any advice or instructions would be greatly appreciated