Check out the Opera Consonance A120 or A100. I have an A120 which I bought here. It is a very solid amp which received a great review at 6moons. I actually went from a Virtue M901 to this and am quite happy with it.
A used Musical Fidelity M series amp might be a good choice as well.
A used Musical Fidelity M series amp might be a good choice as well.