Any advice? Parasound A21, Ayre V5xe, Benchmark AHB2, or Bryston 4B3?

Morning, I am thinking of upgrading my Musical Fidelity M1PWR Monos but would appreciate advice on which amp would fit my Harbeth 7 speakers best.This is a set up in my home office and I do not want an amp that runs hot. I have the opportunity to buy one of the following:Ayre V5xe ($2,500)
Parasound A21 ($1,500)
Benchmark AHB2 ($3,000)
Bryston 4B3 (~$3,800)Thanks.