The V-4's work fine with KT88's, KT90's, EL34's, 6550's, and 6L6's. I always liked the Ei KT90's in my V-4's. I did not like the EH KT88's. I have also used Tesla EL34's and they sounded really nice but not as powerful as the KT90's.
If you like female vocals NOS GE 6L6GC's sound very good although they only put out around 90wpc.
If you like female vocals NOS GE 6L6GC's sound very good although they only put out around 90wpc.