The JJ's are pretty stout, also really liked the NOS Tesla's that KCA use to have. To me warm and El84's don't really go together!
You're going to have a hard time battling that upper-mid focus el84's have no matter what tubes you get.
It really depends on your amps circuit & the inherent "value" of the caps & resistors too. I've installed Mullards, JJ's, SED, and NOS RCA has it's been close. Also: spray out your tone pots to get as best a response. Check your bias too.
If you mean focused, contrary to the way el84 tubes characteristically compress and smear under overdrive, GOOD LUCK. Go to 6V6 tubes if you want focus and warmth...
