In case you want to try out tubes, I’d suggest reading some of @andris’s posts such as this excellent DNA Stratus vs other tube amps comparison. Not only is he a good writer, but Andris has a Utopia and a very revealing DAC (Chord DAVE & M Scaler), and his posts will hopefully provide you with enough parallels to the gear that you either own or have listened to in the past.
I’ll also suggest adding the ampsandsound Nautilus to your list. I don’t have a Utopia, but I do own a Stellia and it’s a wonderful pairing IMO. The one caveat with the Nautilus is that some have noticed noticed noise with super sensitive headphones, but I’ve never had that problem with mine.
Do you mean balanced inputs or outputs or both? I believe the boutique tube amp manufacturers such as DNA and ampsandsound will customize their amps to include balanced inputs and/or outputs if they’re not already part of the amp, but you can always use an XLR-1/4 inch adapter for your headphones, without any degradation of the sound. I do use the XLR inputs on my Nautilus, but that is only to lower the noise floor, per the manufacturer’s recommendation.