Besides sonics, the RIAA EQ curve accuracy is very important. You probably won't see much info on that. They can be tested, I use an Audio Precision analyzer with an inverse RIAA function. When used, it shows the error or deviation for the ideal curve. Most phono preamps have a wavey response, not flat like you want.
If I were to archive a vinyl record, I would choose the most transparent RIAA preamp I could find. Older Neve stuff is know for it's distortions and colors.
You can also build one for a few dollars. A good schematic can be found on the National LME series opamp apps notes.
If you get deeper, there are all sorts of opinions about a active gain stage and passive RIAA equalization or an active EQ topology.