They sound like great speakers.
It seems there was a discussion about solid state and this amp in 2011: https://forum.audiogon.com/discussions/solid-state-amp-for-merlin-tsm-s?sort_order=asc
As for power, if this review is correct, they should be easy to drive with a range of amplifiers:
Impedance: 8 ohms nominal, 6.5 ohms minimum, 14 ohms at crossover point
Sensitivity: 87 dB, 1W/1m (2.83V)
Power handling: 80 watts (program)
https://www.tnt-audio.com/casse/merlin_tsm_e.html
The review makes a mistake, though. It says, "The manufacturer claims these are a "friendly" load for the amplifier. I’m not 100% sure. First of all the 87 dB sensitivity requires quite powerful amplifiers, unless you listen at moderate levels and/or in a small room."
My sense is that with a 6.5 ohm minimum impedance, they should NOT be hard for a wide variety of amps to drive. But the phase angles of the impedance changes are important, too, and I don't know what they are.
All that said, I think with a small, sealed, bookshelf, some power might really open up their soundstage and dynamics. A tube amp with really good transformers is important. In that regard, I’m a Quicksilver fan which has amazing transformers.