I just asked the same thing.
http://forum.grailtone.com/viewtopic.php?t=18526&sid=fe884b3a97e8feff882d590e0b99aa13
I think i may go with either the El34's or the power sections from the "Personal Favorite" That was one of the options the guys over at eurotubes suggested based on the criteria i listed(Warmer sound, break up sooner, crips cleans)
I sent Eurotubes and email and this is some info i got, it was regarding EL34's but they seem to think a 6V6/KT77 combo would give me the best of the El34's and more.
All of the KT (kinkless tetrodes) tubes are very smooth and dynamic where as a typical EL34 is kind of two dimensional and the E34L is like an EL34 on steroids. Basically the two options I threw out there are the warmest and most dynamic options we offer. Nine times out of ten when somebody brings there dual rec into the studio they leave with either the KT66/KT88 or the 6V6/KT77 set up.
This is what i'm most likely going with :
Another option that we have been using in lots of Dual Recs is an Integrated quad using two 6V6’s in the middle two sockets and two KT77’s in the outside two sockets. This gets a great clean tone and the 6V6’s have a deeper thump than 6L6’s do. At higher volumes the 6V6’s break first and the mixture of these with the complex harmonics that the KT77’s have is a killer combination. These are run in the EL34 mode using the GZ34 rectifiers in either the Bold or Spongy setting.