Luc, my opinion is that you should first try just the 1018 with the M80's to see if there is anything you don't like.
Then, if you decide you REALLY want to try using an external amp, I would not mess with older integrated amps or older AVR's. There is too much to go wrong over time with all the switches. And it is questionable to me that you would notice improvement over the amp section in your 1018.
For that much money, I would try to find either a decent used, dedicated power amp or a
Refurb Onkyo M-282 at clubonkyo for $159US.
