There are many approaches with merit, and they can all work.
IMO, if you're going to go with Superhonestben's system approach, then it's
going to be a heck of a lot faster and easier to visit a couple dealers (or local
audiophiles) who have assembled systems, and done the matching. Listen
and pick a system you like and buy exactly what comprises the system.
Otherwise, there are too many variables and potential pitfalls. IMO.
My argument in favor of first identifying and buying a tube friendly speaker
you like eliminates the potential pitfall of buying an amplifier that does not
match well. A tube friendly speaker (high sensitivity...90+dB, nominal 8 ohm
impedance with dips no lower than 6 ohms), will successfully be driven by
just about any PP, or OTL tube amp, or SS amp. Then, if you want a certain
coloration, which is always personal preference, it's a matter of identifying an
amp that provides what you want. A tube friendly speaker will allow easier
experimentation with amplification, which is usually what happens with most
folks in this hobby. How many audiophiles do you know who buy a system
and leave it alone? I don't know one.
Perhaps the system approach, considering one that includes a tube friendly
speaker, is a worthwhile endeavor.