Quick silver M100 best tubes

I have the Silver monos, output is over 112wpc from 2 output tubes. Sonically I like the JJ KT88's. There has been some concern with others about reliability so this may be an issue. You can't go wrong with Winged "c" Russian tubes. I tried them and they were good, but I still liked the JJ. I also heard the Genalex KT88, not very musical for me. A bit mechanical sounding. The Sovtek KT88 was good, good power, but a little soft in the bass. The Chinese tubes from Quicksilver are said to be good, but I haven't heard them with my amps. They were good in a friends amp though. The JJ's have been good to me, but others haven't been so lucky. Try the Winged C, Ram KT88's, or Quicksilvers tubes, those are your most sure bets. I also tried the KT90's. If you like sibilance, these are for you. I used the Ei KT90, and the SSSSSSSS were so painful......a saliva serving with every sss note.
Look elsewhere....I use them in the bass in a Magnepan 3.6 biamped system with a total of 4 of them. Jallen

I really disagree with your assessment of the Gold Lion reissues. They are the richest sounding well rounded tonally balanced KT-88 in current production.
Jim McShane on Audio Asylum tubes is the dealer of choice when it comes to current productio. He burns in the tubes eliminates or culls the bad ones about 5-10% per case. He throws them out doesn't sell the losers as is on ebay. Only then does he Gain match and he noise tests them all.
For older tubes if you seek quality control try Jim Sautter here on agon another very careful seller but he has almost nothing by way of New products but it couldn't hurt to ask. McShane sells old stock but clearly prefers the current production tubes for reliability. Jim Sautter seems to conentrate on providing the high quality tested several times and is very concerned with matching. He understands the desireability and the romance only a OS tubes have.