You want different characterists on these valves for jukeboxs than guitar amps.
I repair and have a good knowledge of both (yes I know - blowing my own trumpet a bit).....
12AX7/ECC83 are the same
12AU7/ECC82 are the same
One code is generally the UK code and the other - USA.
You can get different 'gain levels' on these tubes.
If the 12au7 is being used in a phase splitter both halves of the valve need to be balanced (ie both sides have the same gain number).
Guitarists want higher numbers for the gain stage to get better overdrive. I would not recommend these for jukebox use. You want a mid gain level.
Watford valves sell a lot of snake oil.
Best place in my opinion is Hot Roxx in Nottingham.
Also different valves have differnet tonal differences - but that is another can of worms.