Many of the pitfalls users are describing that torpedo tube amp performance are just poor speaker design. So I'll add to my suggestions: Buy a well designed speaker.
It does not have so be 8 ohms or above. My speakers are 4 ohm, but they are very, very flat and very well designed. I bought them to use with an ss amp. The first time I heard them with a tube amp, I promptly sold the ss amp.
Jerry