Welcome!

In reply to:

I like the setup of the M80's with the dual tweeters and midranges...



I do too.

Members of this forum rate HK very high and most say the HK line has more power than rated (75 watts per channel @ 8 ohm). M80s are very efficient. You should be fine unless you listen at deafening levels.

You could buy a 2 channel amp for the 80's and use the 520 as pre/pro. 80s do thrive on power.