Jeez... For $4k, there's a LOT of great gear available new that would happily power those KEFs! Some examples...
Parasound HINT 6 $3,200
Rotel RA-1592 MkII $3,200
Music Fidelity M6si $3,000
I owned the GFA-555 for a couple years and upgraded to the GFA-555 II when it came out. That 555 II served me well for 26 years without a single hiccup. I drove everything from Polk Audio SDA-2s, to Boston Acoustics A400, Magnepan MG1.4 and 1.7s and a few other in-between. I then sold it for...
This is all you need. At .90/ft, it's a steal. Super flexible, looks great and high quality. http://www.knukonceptz.com/home-theater/speaker-wire/kord-speaker-wire/sp/kord-ultra-flex-10-gauge-speaker-wire/
The irony is that I have spent many, many, many thousands on audio equipment over the years, but the one piece of gear that brings me the most pleasure, is my $800/pair of Edifier S3000PROs. The combination of convenience and surprising sound quality continues to astound me.
Basically, physical mediums are essentially dead. Sure, vinyl has made a minor nostalgic comeback, but its revenue is just a drop in the bucket. As "Hi-Def" streaming becomes more and more common, SACDs will essentially go the way of the 8-Track.
Most "audiophiles" recognize that equalizers in the analog realm can do more harm than good. However, in the digital realm (DSP), they can have a remarkable benefit. Powered subs and speakers benefit with extended and flat responses that would be difficult or impractical to implement with analog...