These Vandersteen Treos don’t need an amp with big "current grunt" as they are a very easy benign load, but they are not very sensitive so they need quite a few watts
Class-D could be good, I can vouch for Belcanto Ref 600m monoblocks, they can sound nice, even in the upper mids/highs into these kind of benign loads.
They do 340w@8ohm and 600w@4ohm. And they are now 5 years old, so used ones are also an option.
Treo’s voltage sensitivity was a low 82.5dB(B)/2.83V/m, the same as the BBC LS3/5a. However, the impedance remains between 6 and 10 ohms for almost the entire audioband (fig.1), with a benign electrical phase angle. The minimum magnitude is 5.5 ohms, at 26 and 75Hz; the Treo will be relatively easy for the partnering amplifier to drive.