I try and be helpful as possible and if I just can’t go along with the premises of the question, I’ll suggest something different.
Something I don't understand...if GanF is the future of amplifiers...for a variety of reasons including the ability to get distortion close to zero and higher order distortion in a proportion so as to not cause the sound to be harsh...then why isn't GanF also the future of preamps.
Now granted that class a preamps use very little energy...but still, why not GanF in order to get the "best" distortion profile?
As for the OP's question...it's going to come down to a matter of trial and error to get the amp/preamp combo that result in the sound that is the most pleasing...to your ears, in your room, with your speakers....and since the Aria has a preamp out, your starting point could be to use it as a preamp for whatever amp you decide to try...you may decide you like it as a preamp and decide to keep it.
I built 3 Gan stereo amps from Gan Systems boards and a Starcrimson set of boards.
ASR had their typical reviews of Gan Amps which really has no listening / sound metrics. The Gan systems boards have the ability to turn off loop feedback and I preferred that vs the feedback even though it "technically" has a lesser spec.
I had several SS amps I owned at the time and sold all after getting the Gan amps. Gone are my Levinson 333, Burmester 956 and Telos 200. I kept 2, The Symphonic RG1 mk4 and a clone DartZeel.