John:
As far as Getty goes they have a list of acceptable cameras. These are the cameras that made the list:
"Canon EOS: 1D(Mk1,2&3), 1DS(Mk1,2,2n&3) 5D, 30D and 40D; Nikon: D2X, D2Xs, D3, D200, D300 and the Leica M8. All medium format backs (e.g. backs by Phase One and Leaf etc) produce sufficiently high quality images to be accepted by us."
From Getty's web site.
Mike Karlsson
PhotoSource International
www.photosource.com
mike@photosource.com