Joe, the link has text but no attachment. If your issue is trying to get a 17 x 14 image scanned, have you considered scanning it in 2 or 3 sections on a conventional flat bed scanner and then stitching the pieces together in
PS? There are probably some photo service providers able to scan something that large but it would probably be costly. As for photographing it, that might work, however what out for lense distorion.
Regards, Murray