It's rated at 88 watts into a 6 ohm speaker but can be used with speakers greater than 6 ohms safely. The power with an 8 ohm speaker would be 66 watts so if the speaker were 8 ohms you would want it to work well with that amount of power.
You would not want to use speakers below 6 ohms. It would probably make the amp go into protection, blow a fuse, or blow up.
The size of the room, how far you sit from the speakers, and the speaker efficiency all also affect what speakers are right for you. Of course you have to like the sound of them which is a matter of personal preference. Go to a shop and listen with your own music if you can. There is no online substitute for that.