Amp/Preamp Synergy for 6K Used

I have a VAC standard LE preamp running into Quicksilver V4 amps (120w)and they work very well together. You can find the VAC for ~$2k w/o phono and the Quicksilver V4's for ~$2.3k.
I think the phono section from VAC is an additional $500-$1k.
I picked up the Quicksilver V4's new for $3k. If your interested I can give you the dealer name.
VAC & Quicksilver are both build solid reliable equipment.

IMHO synergy between amp and your speakers of choice is more important. I would start with Speaker – Amp pair and then selected preamp and front end.
Generally speaking I would stay with products of the same manufacturer. I lived with BAT Vk-5i + Vk-60 + Vk-P5(phonostage) for a while. Works very well with moderate to high sensitivity speakers. Could be had for slightly over $5000. You will have some money left for tube upgrade, interconnects etc.

I had an Ayre V3 and K3 w/phono section and thought they were amazing together. They ran Vienna Acoustics Beethovens and I used a Linn LP-12 turntable. The Ayre's are available for good discounts used. I sold them and downsized to an ARC tube integrated w/small monitor speakers.

And I meant to add that the Ayres sounded very tube-like in my system.

If I had the dollars the CJ 12's and 16 preamp for sale right now on Audiogon would be GONE and in my room. I can't imagine bettering that combo without massive dollars.

Have fun