I don't think the OP is going to go a Nikon 9000 and start scanning at home. Unless he is a masochist. He can send them into a lab and get larger scans, or take that special frame to a lab for scanning and email it out. Or scan the print on an Epson flatbed. My deliverables for years were 11x14 C-Prints, which were then scanned and printed in magazines. Sanning a 4x6 on an epson, making some corrections and emailing it out would be more than fine.
Negs scan way better than positives. I've scanned well over 12,000 images on everything from Nikon 8000, 9000, 5000, Microtek 120tf, Polaroid Sprintscan 4000, Imacon 343, 646, 848, Epson flatbeds of all flavors, and the only times I had heart palpatations was when scanning chromes for a dead line.
As to color neg and quality, I, and many others, used color neg film for almost everything, including high end publications. I only shot Chromes for a certain look and for beauty where the clients demanded it. There is something special about looking at a chrome on a light box, especially an 8x10. Breathtaking.