You don't say what you currently own. That would give us a better idea of your tastes.
The SP20 is the current Audio Research preamp with phono.
Starting with the Ref 2 mk2 / LS25 mk2 / LS 16m mk2 Audio Research used the 6H30 tube instead of the 6922 tube. These preamps are more modern and neutral sounding with a bigger more 3D soundstage. I have owned both types over the years and really like the sound of the newer 6h30 preamps in general.
You also don't say what your budget is, so it is hard to make a recommendation. but you are probably better off with a separate phono stage. especially if you have a MC cart. I own a Ref 5se and use a Fosgate Signature phono stage.