What 2 channel Amp would you Buy for $6k?

Audio Note (UK) Vindicator Silver Signature (2A3 SET).

You’ll be amazed at what 3.5 watts can do, with some good SET friendly speakers (90+ dB efficiency), like the AN Es.

If I had $6K to drop on a power amplifer, I would buy a pair of Arion Audio HS-500 hybrids.  I have heard these several times, and they are excellent.  Lots of power, and they don't sound like Class D amps.  Liquid and clean.  ArionAudio.com.

mc452 here.  So far a fantastic amp!  Also c52 pre.  The solid state preamp made all the difference imo!  Great punch with great detail!   

For less than that I can sell you my Line Magnetic 219ia. Mint condition, gorgeous sound. Magnificent amplifier, just not what fits me best, it's a shame...

My opinion: Get a Decware Zen Triode $1300 + invest the other $4700. YMMV