Any of the Sansui QRX models were rated for 4-8ohm. QRs were rated for 4-16ohm. Only restriction is they do recommend you match output on all four amps.
There's a receiver exactly like this one (Sansui QRX8001) for sale here in Gainesville. I've had a chance to hear it driving some KEF Reference 102/2's, and it sounds damn impressive.