To do better than the PSVANE Hifi series, you'd have to go for a pair of Shuguang 300B-Z/2 Matched Pair Black Treasure, but that's already a lot more expensive. Listening, they're more precise but less warm. Then, to get the very best 300B tubes, prices go crazy!
I agree, those 300B-Z treasure tubes sound really good. I bought a spare pair for my 300B amp after listening to them.
I agree, the 300b PSVANE HIFI series is very good and reasonably priced.
For the price, the Psvane (pronounced "pavane") sounds excellent and is very reliable.