I picked up a Philips SPC900 in the IIS for-sale and have changed the colour sensor to a mono sony sensor. Same sensor but mono version.
Works ok but need to firmware flash it for RAW mono output. Apparently the "mono mod" should give around 3X the sensitivity of the colour sensor but now I need some 1.25" filters and wheel....should have thought of that hey!
Anyway ...I'll get that later.