Bulk convert from PNG/TIFF to JPG with minimal loss in quality

I need to upload my photos to Shutterfly, but they don't seem to support EXIF data on PNG/BMP images. I need to thus convert to JPG for some prints, but I want to lose as little information as possible because the prints will be large format. Is there any way to efficiently bulk convert PNG/TIFF images to JPG with a minimal loss in quality (using imagemagick or otherwise)? The relevant point is that they will print location/time on the print if included in the metadata. I would like to make use of that feature.