I use a cannon S80 8Mp point and shoot camera, copy stand, two 500watt 3200 kelvin hot lights at 45 degree angles to the artwork. Set the white balance to Tungsten and bracket the image both above an below indicated exposure until you have a feel for the right exposure range for your images. Edit in Photoshop until the image looks as close as possible to the original print. You will never get it exact. You don't need a high end digital camera and you don't need RAW format for web publishing. I have found that focal length of the lens really doesn't matter when everything is perpendiclular and parallel on a copy stand. Zoom to fill the frame. You can see results of my 12x20 work at www.bobherbst.com. Some of these images were actually done with a 3 Mp camera. Be sure to look at the posted images on other peoples' computers to be sure brightness and contrast are adjusted accordingly for a good image on the average system. You may calibrate your monitor but the average person does not. Good luck.

Bob Herbst