I am not sure how many PL owners would pair a $3K tube pre with a $1K Class D amp.
I do the reverse ... a PL Prologue 5 power amp with a Musical Fidelity SS cd player/ preamp (CD PRE 24). I also have a Rogue Sphinx v3, which would be the configuration that you are looking at, but the pre stages are not in the same league.
Rather than suggest a $1000 Class D amp based on reviews, why not give a call to Upscale Audio and ask them what they would recommend.
Best regards,
Rich