I don't know about JRiver . . .
Once data storage became affordable I was ripping all of my CD's into WAV files but in the last 6 years I've switched over to FLAC at the highest bit rate possible. I briefly dipped my toe into 24-bit/96kHz Hi-Res digital files (HDtracks, etc.) but couldn't discern any noticeable difference with my CD's, which are 16-bit/44 or 48kHz.
Here's a good tutorial on the subject.