GR settings
Adobe Camera Raw settings below.  Also my base preset I use for GR photos is at the bottom of the document. 

 It looks like the preset defaults are all kept except for Exposure, Highlights, and Shadows.  The default was a little to bright, so I brought down Exposure (this lets me get the midtones where I want them), raised Highlights a bit so the street out the window looked like it was rolling off correctly, and reduced the Shadows to make the darks in the images sufficiently dark.  Its always tempting to do the opposite with Highlights and Shadows, but there is where I think you end up with that almost-HDR digital B&W look.
 My Leica Monochrom and Sony B&W presets is ultimately based off this same GR one, but the GR photos might come out a little spot on with less tweaking.  One thing you have to change is the grain settings - as the image size goes up, I find different settings have to be used.