Best speakers for Pioneer SX-1250 receiver

SOME QUESTIONS PLEASE REGARDING A VINTAGE PIONEER SX-1250 RECEIVER (160 WATTS PER CHANNEL INTO 8 OHMS/200 WATTS PER CHANNEL INTO 4 OHMS). WHAT ABOUT THIEL 2.5 OR PROAC 2.3 OR SOME OTHER USED SPEAKERS IN SAME PRICE RANGE AS THIEL/PROAC. DUE TO THE AGE OF THIS UNIT, WOULD IT BE ADVISABLE TO UPGRADE THE POWER CORD TO A IEC CONNECTION THAT WOULD ALLOW FOR A VARITY OF POWER CORDS. ANY OTHER SUGGESTIONS FOR THIS UNIT THAT IS IN GREAT CONDITION? THANKS.