You may also want to try a set of CBS or Hytron shiny black plate 5814s from the late 50's and early 60's. One of my all around favorite U.S. made 12AU7 variants.
What experience have you had with 5814a Tubes?
I've had a super positive experience with 1950s NOS 5814a tubes, triple MICA black plates. I think they sound superb.