I wouldn’t want to leave a tube power amp left unattended for hours on end. I also can’t see the clock running wasting tube life of the power tubes. Average life of power tubes being around 1500 to 2000 hours.
The solid state amp sounds like the way to go to break-in the new speakers. Not sure I would go with the cheap amp you are considering buying though. Why not buy a better quality used amp for just a little bit more money.
You also might want to consider a used 2 channel receiver. You can then use the FM tuner for the music source.
If you have a B&M dealer in your town you want to check if he has any used equipment he has taken in on trade in.
You can also pick up a great used 5.1 A/V receiver cheap.