My top choice would be bring back Bogaerts. I’d like to see a return to OBP, with whick Kike brings back very little whereas Bogaerts is in the top ten in MLB over the past 3 years.
If the Sox do bring in an FA, Kolten Wong and Adam Frazier are the closest matches, but neither really excels at OBP. Jon Berti from the Marlins is an interesting target as he does get on base and is arb eligible in Miami, which often makes a player available. That he plays everywhere certainly helps and fits the mold of numerous players (Taylor, Muncy, J Turner) Friedman grabbed in LA to supplement that team.