Hi 1j,
welcome to the forum!
Although the similaritiy of our nicknames it is quite funny, I would not have assumed that you wanted to make fun of my nickname
You wrote that the KT77 were the best tubes for you. I do not know what exactly you want to hear or know from me because I do not know what "best" means for you personally. According to my experience the question "which tube is the best" depends on two things:
On the one hand one must think about the musician's personal taste and therefore the tonal properties of the tube in interaction with the circuitry around the tube. This means that it depends on the amp, on the settings, on the style of playing, the music genre, the speakers, the guitar and so on. I call these aspects the subjective ones.
On the other hand there are objective (technical) aspects as well. Some tubes are - for example - not rated for high screen or anode voltages which can be found in some guitar amplifiers and therefore cannot be used as a replacement for another tube type although this might work in a different type of amplifier. You can even find some tubes of equal type label but from another manufacturer that have a different rating. Of course you should also think about the tube's durability (mechanically and electronically). Some tubes are highly durable, other are rather shock sensitive or crack easily due to thermal stress and so on.
I do not know why you want to use KT77 but if you give us some more input about your motivations to do so we could tell you some more options or manufacturers or other things.
Personally, I never used KT77 and I do not use chinese tubes because I had many problems in the past using tubes from that origin so we have to rely on other people's experience with KT77. But that should not be a problem since there are some skilled people on this forum who can help us on that topic.
Regards
1st1