Do you need a phono pre-amp? If not, restrict your search to the AR linestages (model numbers bear an LS prefix). Otherwise, you will want ot look at the SP models.
The better AR products seem to all have balanced design. In your price range, you can look at the LS15, LS16, and LS22. My understanding is that the LS5 MkIII is one of the best linestages that AR has produced. It is, however, more than $2000, and if you are using any single ended sources or amps with it, you will need adaptors (no big deal). Adaptors are not required for the other linestages mentioned. If all your gear is balanced, you can use the LS5MkII also (less than $2000.).