Fast & open sounding amp with great imaging 2k

I have 92db 8Ohm single driver speakers and I want to get more micro dynamics, detail, an open soundstage, and solid imaging out of them. Looking for recommendations. Budget 2k (2nd hand gear only)

on my list:

clones audio 25i
job 225
Benchmark AHB2
Aaron XX
Mystere IA11
Unison simply italy