My first amp was a jcm800 100watt. I wish I had never sold that amp. Then I had a jcm800 50watt. The difference in volume ie db, was barely noticeable. That amp cranked, however it was extremely hard on tubes $$$$. Then I went solid state for some time, WHAT THE FUCK WAS I THINKING. Sure it saved a lot on tubes, but FUCK ME it was NOWHERE NEAR as loud, the tone was ass & when I finally got my hands on a power amp that was as loud (& expensive) as a tube amp, it blew not one but 2 quads up.
When solid state amps hit clip, they clip square & fry speakers. When valve amps hit clipping they naturally compress & round the edges off. Hence more volume & no blown speakers.
As for the Rivera knucklehead 50. It should be plenty loud enough. It has the tone that will tear a nice mid eq'd hole right through the mix. It is like a vintage marshall but louder & better.
The guy who started Rivera used to work for Fender. Then spent years modding & improving Fender & Marshall amps. Eventually he went down the Soldano path & decided to use what he had learnt to build an amp with all the best characteristics of a Fender & Marshall, eliminating all the things that he & his customers disliked. He nailed it & The rest is history.
Seriously, go try the Rivera out. You will either love it or hate it. It is that kind of amp. It does what it does to perfection & does not pretend to be an amp that can do everything. It is a no compromise BALL TEARER.
Hence the list price new of around $4000. They are asking $2000.