I have been spending some time generating .icc softproofing profiles from QTR, an excellent bit of software.
I realised that you can use softproofing, and eventual conversion as a way to generate B+W images from color images.
Essentialy you need to turn on softproofing and select a QTR profile, the image goes B+W. Now apply a Hue / Saturation Layer and tune to taste. A curves adjustment layer allows contrast tuning too. You then need to convert to the QTR profile, and eventualy to RGB
Added a page to my web site to describe it in more detail.http://www.colourperfect.co.uk/11.html
As QTR allows toned profiles (warm and cold) this can be used as well