First of all, it's not 8 ohms "normal" resistance, its 8 ohms "nominal" resistance, and the word nominal in audio means something like: This is an even less meaningful spec than the others.
Resistance varies with frequency, and the more valuable figure is the minimum load, since that's a better indication of how the speaker will tax your amp.
Also, the fact that your amp specs give a power rating into 8 ohms means nothing. The manufacturer could also have given a power rating into 4 ohms (which would probably be higher).
If you're going to pay attention to specs, you have to know what they mean--and even more important, what they don't mean. In this case, they don't mean much. Buy the speaker that sounds best with your amp, in your room, and you'll be fine.
Resistance varies with frequency, and the more valuable figure is the minimum load, since that's a better indication of how the speaker will tax your amp.
Also, the fact that your amp specs give a power rating into 8 ohms means nothing. The manufacturer could also have given a power rating into 4 ohms (which would probably be higher).
If you're going to pay attention to specs, you have to know what they mean--and even more important, what they don't mean. In this case, they don't mean much. Buy the speaker that sounds best with your amp, in your room, and you'll be fine.