There's nothing special about old 8 ohm speakers that would require a tube amp. Any modern solid-state audio-video receiver will work fine with them. Just because all they had were tube amps when those speakers were designed doesn't mean that you have to use tube amps today.
Using tube-based electronics electronics these days is a life-style choice. They're much more finicky than solid-state electronics, but many people like them despite their higher operating cost. (Tubes have to be replaced regularly, for example.)
With old speakers, though, there are some mechanical and electrical things you need to worry about. The capacitors in their crossover networks may have failed, for example, Also the "surround" material which connects the speaker drivers to the enclosure as well as the cones of the drivers themselves may be dying, too. Check for cracks in the material.
You should consult with people in the speaker forum for more information about the kinds of refurbishing that might be needed.
Marantz SR7009 avr + MM9000 amp --> Atmos 7.1.4
Fronts=NHT 2.9+AC2, FH+TM=DefTech PM1000, LCR+TM amped