@immatthewj having dealt with both of these characters on amps, different tubes, options, I’ll say you are a bit on your own until you partner with a great local tech who can open up these amps and tell you what’s really going on inside of them.
I’m always leary of tube resellers who are likely trying to sell you what they have on hand or can get easily vs something they dont’ have on hand or need to order or cannot get so easily during different cycles of tube availability any given month of the year. Yes, and, Dennis did and still does "voice" his amps [in his own mind] trying different circuits, tubes, transformers, and more to achieve a different sound that he likes. Having owned various Cary Audio and Inspire by Dennis Had amps, all of them sounded different in triode, strapped triode, ultralinear modes too. And, my other ultralinear circuit mono tube amps sound different yet again from the former Cary and Inspire amps. Voicing, Marketing, whatever - back to listening to be the final judge of what you like and hear for your own system :)