@bonzo75 you know my love of symphonic line, so i am 100% with you on that. that said if he likes his current amp or dealing with trade out etc is a pain i totally understand.
@Newtoncr, where are you based? if you're in the states and are intrigued by symphonic line (don't let the lack of coverage here dissuade you - im obvi a fan boy but the amp is an absolute demon), give klaus at odyssey a call. for me, the only question the sl kraft has left is...what would 2 of them sound like? i think it would pair beautifully with your pre.
while it's a powerful amp, its less about the power and more about the tone it brings. for example, the alsyvox do not need that kind of power but if i were to get one i'd keep the amp because i bet it would sound fantastic on them as well.
new amps and stuff aside, when i was looking into the sonja i talked to bill over at GTT Audio. he mentioned that he has a client running sonja with sl and it was a great combo.
however, if you're set on your amp (given it's quality, nobody could fault you for that), i believe an easier to drive speaker would be a better pairing. if i had to make an educated guess, i believe the ayre stack would sound great on vocals and small scale jazz. for pop and rock you're going to want more. in my experience, both magico and yg sound dynamically constrained until given lots of power. one of those things where you only really notice it when you've tried it. ive run lower watt amps on 87-89db speakers and they all sounded great but throw a few hundred watts and high current and the speakers open up and get that "stat like" presence everyone always mentions.
the good news is that high powered ss isn't that expensive to do well. you don't have to go the flagship route...something like the kinki studios with job circuit, or odyssey amps (full disclosure, i'm selling mine soon. not soliciting but also don't want anyone to feel like i'm saying this just because i'm listing mine soon), or a vintage ss. you could snag any of these for cheap and just swap it in for when you want to really rock out and keep your ayres for the rest of the time.
the doubly good news is that you have tons of options in your budget range and already have a great set up. so there's lots of directions you can go in that will all lead to excellent sound.