Digital BW, The Print

OK so I've been having a lot of fun but I'm having a hard time with
soft proofing. I have a Epson R220 and have been making some prints
with the Eboni Black on EEM BO. I find printing with gamma 2.2 too
dark so I've been printing at 1.8. Secondly, I find if I print with a
viewing mode of RGB in PS CS, I get a lighter print that more closely
resembles what I see on my screen compared to printing from a
Grayscale viewing mode. I think that has to do with how the printer
handles the conversion since the Grayscale image and RGB image look
the same on my screen. Now I haven't made a Grayscale print at gamma
2.2 yet-I'm going through a lot of paper...

Source Space 
Document: 20% Dot Gain
Print Space
Profile:
Same as Source

Any thoughts would be greatly appreciated:)

Scott