I'm looking to get an amp to power some vintage Acoustic Research AR-3a speakers in a second zone (another room from my receiver). My receiver has multi-room capability.

This is the amp I'm looking at:
(second from the top - Yamaha A-1020)

The AR-3a's are reportedly power hungry and 4-ohms. If you look in the following image, it has a description of all the impedance capabilities of the amp (which confused me):

I also have a set of small (cheap) outdoor speakers rated at 4-ohm, wich I could connect to this amp.

Thank you!!