Digital BW, The Print

What do I need to know about choosing a grayscale working space. I've tried
gamma 2.2, dot gain 20%, and no color management. Frankly I do know what the
heck I'm doing here.

FWIW, I ultimately convert the file to Adobe RGB in order to use Roark's
Variable-Tone method, but I keep an archive of the files in grayscale too.

Suggestions?

Todd