I believe the Philps PCC88 tube that I linked earlier (Tube Depot) is/was being sold by c-j. If I'm not mistaken, I was told the c-j buys that particular tube. Below is a link from a post on another forum. That was one person's experience with tube rolling with the ET-5. From what I've read, it is harder on tubes than some of the other c-j preamps. The tubes in my PV-14L lasted for 10+ years. I didn't have the Premier 17LS2 long enough to burn through any tubes.
I am reporting back as promised. The tube I am using is the Philips E88CC, a NOS military tube from the 1960s. Jeff at cj can supply them. They are the best tube overall that I have tried. They sound warmer overall than the EH and hold up just as well. The EH tube is good too, sharper, brighter.
The Gold Lion 6922 sounded great, perhaps the best of all, but it got noisy very quickly.