Congratulations Lars, welcome to the Homage club. I believe the SF Stradivari are some of the best speakers in there class and a classic which is probably why they made 35 pairs this year to celebrate the 35th Anniversary of Sonus Faber. Not to ruin the honey moon period of your new integrated amp. the Strads deserve mono amps.
While the MC501's I have sound incredible with the Strads. and I have no urge to replace them. I like a more musical sound personally to over the top detail which causes me listener fatigue. The new MC611 or MC2301's (if you prefer tubes) will no doubt give you a fantastic combination you will enjoy for years.