I am new to high FidelityBut I’m trying to design a system that has the warm tones of a tube amp with greater more efficient power.
A common enough mistake. In reality its never power. No one ever needs more than about 50 watts. What they need is speakers with sensitivity of 92dB, at the very least. 95dB and up is even better.
Do this one thing and boom! Now any amp 20 watts or more is all you need. The Tekton Moabs I run for example, 98dB, with my 50 watt Melody tube amp fills my 24x30x9 foot room with sound so wonderful you can't believe (if you fall for Danny D' do NOT come hear this!)https://systems.audiogon.com/systems/8367 and will play loud enough to leave ears ringing if you keep it up long enough.
A much, MUCH better choice if you are in that price range https://www.ravenaudio.com/product/reflection-mk2/
Also you need to realize its not just the amp that gives the warm tube sound you want. Its everything. If you do not pay attention to this its real easy to undo with wire and source components and speakers everything you thought you had accomplished with the amp.
So if you are smart you will be looking at speakers like Tekton that are, not warm really, but certainly not hyped up like the vast majority of what's out there. Also incredibly easy to drive. Betcha money since you think you need way more power than you do its because you got sucked into speakers like Wilson, Magico, etc that require massive power. Why? Because they never were designed to work in the real world.
Putting together a satisfying system isn't hard enough already? Why put yourself through that? Simplify. Save yourself a ton of money. Time. And effort. More importantly, way better results in the end. Actually get what you were looking for.