Inexpensive Tube Amps

@roberjerman, "Save your money and buy a REAL tube amp from Will Vincent (autospec)"

I think that's a more than excellent way to go.  Will's standard rebuilds are Dynaco ST70 restorations with upgraded parts and aesthetics.  Considering how many of these amps made 40 - 60+ years ago still work well, you can't go wrong.  With modern resistors and capacitors, what too many consider as the lowly ST70 can hang with almost any modern amp, and beat a lot of them.  And as also mentioned, if you want a different flavor or spin on thing, Will does a lot of custom work

I have a pair of Mirage OM 10 Towers that are 6 ohm and 91 db sensitivity.  Should not pose a problem for any of these.  Also have a pair of Castle Conway 3 Towers that are 8 ohm and at least 88 db sensitivity.  

@will62 None of these amps make enough power to drive speakers with efficiency as low as those in the quote. You would want 10X the power at a minimum.  A Dynaco ST-70 is a good suggestion and there are many versions of that amp available.

If YOU are referring to me, I know this is a different OP. Just informing him that I would not trust a cheap Chinese amp in the long run.
You get what you pay for.

I agree with @atmasphere , although I bow to his expertise.

As noted, many of those economical tube amps from Amazon are made in China. Not a bad thing, but I agree with @lowrider57 : 
the Yaquin is a cut above, also the Cayin's are very good. word has it their integrateds are based on the classic McIntosh designs.

You also have the option of a "DIY" tube kit. but Again, I would not buy indiscriminately on Amazon, but go to an audiophile site that sells them, like Bottlerocket or others out there now that are on their 3rd, 4rth, 5th, design iteration and getting better all the time. 

But as will all things audio: depends on your budget.
But if I were you, I would look for a used Cayin or Yaquin. You pay less, and if it doesn't work out, you can sell it on the used market for the same price you paid and you dont lose money.