A high current SS amp will leave more speaker options open for you.
I'd start with dynamic speakers that can move a lot of air yet still reveal delicate or intricate detail that will fit and blend into your room well and go from there.
I'd recommend staying away from tubes in the power amp at least initially mainly because a good high current amp, say Wyred4Sound Class D, for example, would drive almost anything and cost less and most likely be more worry free in regards to maintenance, biasing, tube replacement etc.
I'd start with a simple single tubed DAC and feed that from the front end of choice. That could be using any decent CD player with digital output, which you may already have even. using the digital output bypasses the internal DAC. The mhdt Paradisea or havana are good ones. There are others as well.
Or, it could be a Windows Vista or Apple computer or notebook running a music server program, like Windows Media Player (see my system for an example) that feeds the DAC.
Then, toss in your good quality pre-amp of choice, tube or SS depending on your lust and/or tolerance for tubes.
For tubes on a budget, the Juicy Music Peach is an inexpensive highly regarded tube pre-amp that I would consider the VTL 1.5 is another.
For SS, Classe or Musical Fidelity would be tghe first choices I would consider.
Musical Fidelity makes some very fine SS amps that would work well also (that is what I use in my system).
Another cost effective option could be a tube/SS hybrid integrated rather than separate power and pre-amp. Unison Unico is a good example of this.
OR the budget basemet option for good sound might be a Peachtree Decco or more powerful Nova hybrid integrated+ DAC, which can be had refurbished these days for as little as $500. One of these would drive most speakers that will be in your price range pretty well I would think in a typical sized listening room.
BTW any of these combos (dynamic speakers with detail + a strategically placed tube or two) should sound pretty good with most any genre of music, including prog/metal.
if you do go with a lower powered amp, then make sure the speakers are more efficient, say 89-90 db or greater.