Inexpensive Tube Amps

You provide very little information on your situation for one to provide reasonable advice. Regarding the amplifiers under consideration:

These are low watt amplifiers to be mated to speakers with high sensitivity and a benign impedance load. Also fits best in a system playing into a small to medium size room and not playing rock music at high volume. If this is your situation, then give one a try. Be careful with the amp and I assume it can be returned to Amazon after a trial period with little monetary loss.  

Yes,  I won't buy anything that does not come with a money back guarantee.

Based upon reviews I've read, people using amps with as little as 87 db sensitivity into 8 ohms are not having any trouble driving amps like these or the Musical Paradise model.  Trouble in Paradise though since that one is out of stock and may be for a while.  They move fast.

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.  

A guy using the Musical Paradise which puts out 6.5 watts per channel has a pair of Sonus Faber speakers that are a mere 87 db sensitivity and he said they are easily driven beyond a reasonable comfort level for audio with that amp.

Medium size room at the moment 15 by 14.  Will likely be in a smaller room in a couple of years since I doubt I will be staying in my present home.

You get what you pay for. Some Chinese gear can be good, but amps at this price range will be riding the very bottom of the barrel. They will have been cranked out of a factory with very little concern for quality or perhaps even safety.

Save your money and buy a REAL tube amp from Will Vincent (autospec). I have his SE45 amp and it is superb! Need more power? Will can build you a 2A3 or a 6L6/EL34/6550 single-end amp! Beyond these PP is needed for more power: his Dynaco ST70 clones are excellent! 

Read the current thread, First Tube Amp. The OP is auditioning a Yaquin, a highly regarded Chinese built tube amp found on Amazon.
  These seem to be a cut above the mass produced Chinese amps and may be a keeper.

Also, sensitivity of the speaker is not an indication of how well a low power amp will perform. You need to look at the impedance at any given frequency.