it's probably a number of carefully lit shots with a phase one camera/back. if you are very careful with positioning you could stitch a bunch of shots with a cheaper camera. definitely read up on lighting art for photography, that's going to be critical. macro lens is probably not necessary. there are a variety of javascript-y things for dynamically viewing large images, shouldn't be /too/ hard to find or set up.

edit: in this video, at 0:25 you can see the setup presumably used. https://vimeo.com/ondemand/jheronimusbosch/146311294