You actually can use any Nikon or Canon mount based digital camera. The medical lens allows only limited functionality even with the latest Nikon mount bodies. http://www.zoerk.com or http://www.novoflex.com offer a mechanical adapter (no optics involved) adapter to mount Nikon lenses on Canon. Actually the Canon's will allow more exposure modes with a non-EOS lens than Nikon does with non-AF/AF-D lenses. Similar adapters can be found to mount Leica-R on EOS cameras, very nice performance if you accept that you have to work with stop down aperture. Right now I am using a Schneider lens on my EOS and the optical quality more than compensates for the stop down metering!
I just compared a couple digital cameras and was surprised about the low quality level offered by the Kodak (DCS14n). The sensor is huge, but the handling is horrible. The current Nikon cameras as well as the Kodak seam not to stand up next to the Canon 1Ds which has very nice signal processing, metal body, a large sensor and a lot less other problems than Kodak or the by now more or less outdated Nikon digitals. Even the Canon EOS 10D offers a lot more than some of the much more expensive competitors. I have to assume that you will use the digital camera not only for work and with the medical lens, so Canon would mean a complete change of system and philosophie for you. I did the same 2 years ago and the only thing I am really missing is a waist level finder - on the other hand I used to miss alot more in Nikon cameras.