Highend:
I have some "unusual" combo’s due to downsizing and keeping cables that I like ($400 BMI power cord and 47 Labs interconnects on the Sharp/Polk/Kenwood mini-system used @ the computer that cost closeout/used/found on the street $83.50).
I understand from one of your previous posts that you really like the speakers, but have you considered auditioning other speakers with your $4K budget - which may cover new amplification as well?
Not written in stone, but generally it’s advisable to match amplification to speakers and not the other way around (this "kernel" of knowledge being directed @ upgrading the speakers after new amplification).
DeKay

