What I mean by Which Tube Radio:

If I bought myself an old used Tube Radio, I would exspect some of the
tubes will eventually burn out, and I would have to replace the tubes in
order for the radio to work.

So, that I could have a radio that I could always find the right tube,
means that I would have to buy a radio that it's tubes are still being
made by a company.

I do not think that I would want to get a radio that I can not replace
it's tubes.

Based on your concerns, I suggest that you should NOT buy a tube radio. Tube
radios are like antique cars, they require a certain attitude.