I would go to HiFiShark and search for names of amp builders like Burgess, Deja Vu, etc. These are small-batch builders who make a good amplifier at a reasonable price - especially if pre-owned. Good 300b tubes tend to be expensive.
SET amps
What tubes are a good balance of great intimate sound and budget? Any suggestions for amp kits and builders? $1500 budget Or so. Any options?