Auto feed scanner?

What do you mean by photo scanner? The automatic document feeder of scanners that have them have adjustable guides to accommodate various paper sizes. Scanning software has selectable resolution. If your scanner properly handles your paper stock and accurately captures color at sufficient resolution, then the device does not need to be labeled photo scanner.

This is not quite right. The pixel density of a scanner is not nearly so important as the total number of pixels in the scanned image. The gold standard for scanning photographs is the drum scanner. You obviously cannot afford a drum scanner. Consumer-grade photo scanners are designed to scan 3x5 or 5x8 photographs. A document scanner can scan 8x10 photographs. My experience with the scan of 8x10 is most satisfactory. It is a poor craftsman who blames his tools. If you are minimally competent, then the print of your scans will blow the socks off the people who view them.