Linestage search

I´m looking for a linestage for my EAR 509´s monoblocks.

The input impedance of the 509´s is 25K

My first options are the following:

1. EAR 868 (used)

2. Coincident Statement Linestage (used)

I didn´t have the opportunity to hear any of them, so I would really appreciate advice on the choice.

Thank you all.