If you're going to stay with tubes you really only have one choice here, which is obviously the Sonatas(which will also work well with SS if you go that route some day). I would also put them at the top of the list from a sonic perspective along with the 3.3s(not really an option with tubes), but that's more of a personal decision. Absolutely go hear the Sonatas before making any final decisions. Best of luck.
Tim
Tim